North Carolina organic grain production guide

North Carolina Organic Grain Production Guide 1
North Carolina Organic Grain
Production Guide
North Carolina State University
North Carolina Organic Grain Project
College of Agriculture and Life Sciences
Prepared by:
Molly Hamilton, Crop Science Extension Assistant, NC State University
With contributions from:
Keith Baldwin, Extension Specialist, North Carolina A& T State University
Gary Bullen, Extension Associate, Agriculture and Resource Economics, NC State
University
Mike Burton, Assistant Professor, Crop Science, NC State University
Carl Crozier, Soil Science Extension Specialist, NC State University
Jim Dunphy, Crop Science Extension Specialist, NC State University
John Van Duyn, Entomology Extension Specialist, NC State University
Myron Fountain, former Executive Director, North Carolina Crop Improvement Association
Ron Heiniger, Crop Science Extension Specialist, NC State University
David Howle, Assistant Professor, Fertilizer and Seed Certification, Clemson University
Tony Kleese, Executive Director, Carolina Farm Stewardship Association
Jim Riddle, Organic Policy Specialist, Rodale Institute’s www. newfarm. org
Phil Rzewnicki, Teaching Assistant Professor, NC State University
Randy Weisz, Crop Science Extension Specialist, NC State University
Alan York, Crop Science Extension Specialist, NC State University
Acknowledgments
This publication is supported in part by a grant from the Z. Smith Reynolds Foundation.
2 North Carolina Organic Grain Production Guide
Contents
Page
Chapter 1. Introduction ........................................................................................................................... 3
Chapter 2. Organic Crop Production Systems ........................................................................................ 4
Chapter 3. Crop Production Management – Corn .................................................................................. 6
Chapter 4. Crop Production Management – Wheat and Small Grains ................................................. 12
Chapter 5. Crop Production Management – Soybean .......................................................................... 18
Chapter 6. Soil Management ................................................................................................................ 22
Chapter 7. Weed Management ............................................................................................................. 27
Chapter 8. Organic Certification ............................................................................................................ 31
Chapter 9. Marketing Organic Grain and Oilseed Crops ...................................................................... 36
Chapter 10. Crop Budgets ...................................................................................................................... 40
Resources ............................................................................................................................... ............ 46
Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the
reader. The use of brand names and any mention or listing of commercial products or services in this publication
does not imply endorsement by North Carolina Cooperative Extension nor discrimination against similar
products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that
the intended use complies with current regulations and the product label. Be sure to obtain current information
about usage regulations and examine a current product label before applying any chemical. For assistance,
contact your county Cooperative Extension agent.
North Carolina Organic Grain Production Guide 3
Chapter 1. Introduction
Phil Rzewnicki, Teaching Assistant Professor, NC State University
Molly Hamilton, Crop Science Extension Assistant, NC State University
The market for organic products is growing at a
rapid pace. In the United States, the organic food
industry grew between 17 and 21 percent each year
from 1997 to 2003, and an average annual growth
rate of 18 percent has been forecast through 2008
according to the Organic Trade Association
( www. ota. com). In 2003, the market growth of or-ganic
bread and grains was over 20 percent, with
growth of organic meat, poultry, and fish near 78
percent. These trends are expected to continue.
To be certified as organic, livestock must be
fed organic grains as required by the U. S. Depart-ment
of Agriculture ( USDA) National Organic
Plan Rules. This requirement leads to more oppor-tunities
for production of organic grains. In North
Carolina, organic grain producers have expanding
opportunities to market their products to manufac-turers
that create foods for human consumption as
well as to livestock feed markets. Organic grain
prices are usually 150 percent higher than prices
for conventionally- produced grain. Other benefits
of organic grain production include increased soil
health, farm income diversification, and lower
levels of exposure to common farm chemicals for
both people and the environment. Farmers in
North Carolina are in a unique position to take
advantage of the early growth of organics by
growing and selling organically produced grain. If
they are to take advantage of the price premium
for organic products, however, more research on
organic grain and oilseed production in North
Carolina is needed. In addition, a network of or-ganic
grain farmers should be developed, and
marketing information and Extension education
should be made available to help growers compete
successfully in this rapidly expanding industry.
This guide provides farmers, Extension person-nel,
and other agricultural educators with informa-tion
about organic production, certification, and mar-keting
of grain crops as well as references to further
information ( see the “ Resources” section, pages 46-
48). It does not cover all aspects of grain production,
but focuses on specific techniques relevant to or-ganic
systems. Comprehensive guides to grain pro-duction
can be found in the latest editions of these
Extension publications:
• Small Grain Production Guide:
www. smallgrains. ncsu. edu/ Guide/ cover. html
• Corn Production Guide: http://
www. ces. ncsu. edu/ plymouth/ cropsci/
cornguide/
Additional information is available from the NC
State University Department of Crop Science:
www. cropsci. ncsu. edu.
This guide does not make recommendations
about the use of pesticides in organic systems. No
research has been published on the use of pesticides
approved for organic production of grain crops in
North Carolina, and we cannot make recommenda-tions
for their use here. The cost of pesticides ap-proved
for organic production may also be prohibi-tively
expensive for field crops. The Organic Materi-als
Review Institute ( OMRI) publishes a list of com-mercially
available products that can be used in cer-tified
organic operations for pest control
( www. OMRI. org). Conditions for use of an ap-proved
pesticide must be documented in the organic
system plan, as described by the 2000 National Or-ganic
Plan ( NOP).
We have made every effort to accurately cite
National Organic Plan regulations, production infor-mation,
and marketing information. Always consult
your certification agency when you have questions
about certification requirements specific to your
particular farm.
4 North Carolina Organic Grain Production Guide
Chapter 2. Organic Crop Production Systems
Ron Heiniger, Crop Science Extension Specialist, NC State University
Molly Hamilton, Crop Science Extension Assistant, NC State University
Organic production systems are based on manage-ment
practices that promote and enhance farm
biodiversity, biological cycles, and soil biological
activity. Organic agriculture strives to minimize use
of off- farm inputs and relies on management prac-tices
that restore, maintain, and enhance soil ecology
and the farm landscape. Growers considering organic
grain crops need to recognize that success will de-pend
on developing a diversified crop management
system, including an appropriate rotation plan. Rec-ommendations
in this guide were developed to help
growers tailor soil health and pest management strat-egies
to fit their specific conditions.
Components of Organic
Production Systems
Table 2- 1 lists the key components of an organic
production system. The choices made for each com-ponent
will affect the choices for other components
as well as soil fertility and pest management.
Table 2- 1. Components of cropping systems
Components Category
Crop sequence Rotations
Cover crops
Crop management Variety/ hybrid selection
Planting depth
Planting date
Plant population
Row width
Harvest and storage
Soil management Tillage practices
Fertility
Pest management Weed management
Insect management
Disease management
Crop Sequence
An organic production system begins with selection
of the best rotation sequence of production crops and
cover crops based on the specific characteristics of
the field. This is particularly important in the first
few years of an organic production system because
the transition period will set the conditions for suc-cess.
Rotation sequences should be designed to:
• reduce weed pressure by minimizing the
amount of weed seed produced and reducing
perennial weeds;
• increase the amount of mineralizable nitrogen
in the soil;
• reduce the incidence of insect and disease pests
by eliminating hosts and interrupting pest life
cycles.
This usually requires combinations or rotations
of crops that attract or harbor different insects and
diseases, fix nitrogen, inhibit weed growth, and en-hance
the soil. The following crop sequences are
recommended for organic grain crop production in
North Carolina.
Wheat – Red clover ( or other forage legume)
– Corn. Wheat and the legume provide continuous
ground cover, help break up pest cycles, reduce
warm- season weeds through the mowing of clover,
and increase available nitrogen. Tilling the clover
into the soil makes nitrogen available for the suc-ceeding
corn crop. Growing the legume for two sea-sons
will result in more nitrogen returned to the soil
and a longer period between corn crops to break pest
insect and disease cycles. However, in systems with-out
livestock, the legume cover crop might have
little economic value unless it can be cut and sold for
hay as an organic forage crop. Cutting for hay will
reduce the amount of biomass from residue and may
reduce the amount of nitrogen available to subse-quent
crops.
North Carolina Organic Grain Production Guide 5
Wheat – Soybean – Corn. This rotation has many
of the same advantages as the above rotation, but the
soybean crop can be harvested and marketed. One
disadvantage of this rotation is longer soil exposure
since soybean is planted after wheat and harvested
before corn. Weeds emerging in the soybean crop may
be difficult to control, and less nitrogen will be fixed by
the soybean crop. However, a cover crop could be
incorporated into this rotation to provide ground cover
when needed, to expand the rotation beyond two years,
or both. A short, two- year rotation will need to be ap-proved
by a certification agency.
Farmers who have long- established organic
fields usually use a longer rotation of four or five
years. A longer crop rotation could rely on one of
these sequences:
• Corn – rye cover crop – soybeans – rye or crim-son
clover cover crop – wheat – cowpea cover
crop.
• Corn – wheat – ( double cropped) soybeans –
crimson clover cover crop – sunflowers or sum-mer
cover crop – small grain ( oats, barley, triti-cale).
Legumes or other broadleaf crops should be grown
at least two of every five years. A well- developed crop-ping
sequence should result in minimal problems with
insects and plant diseases. Weeds are usually the major
issue for long- term organic systems, but even weed
problems can be managed through suppression by
particular cover crops and timely cultivation.
Transitioning to Organic Cropping Systems
A switch to organic production from conventional agriculture requires a 36- month transition
period. Experienced grain farmers can use their skills, knowledge, and experience with conventional
grains as a base to build new proficiency with crop rotation, cover crops, mechanical weed control,
record- keeping for certification, and marketing of organic crops. Most North Carolina farmers already
have rotations that include corn, wheat, and soybeans. Such farms can go organic with little capital
investment; however, mechanical weed equipment, separate storage facilities, or both may be needed for
organic harvests.
It is advisable to begin transitioning to organic with a relatively small acreage and carefully
chosen fields. Fields with low weed, insect, and disease pressures and with relatively good soils give the
best chance of success when starting with organic production. Fields with more intense pest problems or
soil requirements may take more experience with organic production to be successful.
Although crops produced during the transition to organic might be marketed for a premium over
conventional crops, return will be less than for certified organic crops. Some grain buyers in the Midwest
are looking for nontransgenic ( non- GMO) corn and soybeans, which must be used in transitional produc-tion.
Some livestock producers in North and South Carolina are also looking for nontransgenic grains for
feed and are willing to pay a small premium. These markets may be harder to identify than traditional
organic markets, but they can provide economic incentives during the transition years required to change
from conventional to organic farming. Some of these buyers register with this N. C. State University Web
site: www. cropsci. ncsu. edu/ organicgrains/ marketing/ buyers. htm.
6 North Carolina Organic Grain Production Guide
Chapter 3: Crop Production
Management— Corn
Ron Heiniger, Crop Science Extension Specialist, NC State University
John Van Duyn, Entomology Extension Specialist, NC State University
Production Management
Key management practices for organic corn produc-tion:
• Choose organically grown ( when possible),
non- GMO hybrids with high vigor, high
standability rates, disease and pest resistances,
stress tolerance, high yield, and a maturity
date of 112 days or less.
• Plant on time, at the proper depth, in a well-prepared
seedbed, on narrow rows.
• Rotate crops.
• Achieve proper soil pH and good fertility.
• Choose the correct plant population.
Hybrid Selection
For organic growers seeking to identify appropriate
corn hybrids, yield is not the primary consideration.
The key hybrid characteristics for organic corn pro-duction
are
• rapid early growth and vigor
• standability
• pest and disease resistance
• stress tolerance
• yield
Table 3- 1 provides a list of organic and conven-tional
untreated hybrids that have been evaluated and
rated for these key characteristics.
Rapid early growth and vigor
Rapid early growth is essential in minimizing the
effects of seedling diseases and insects, increasing
root volume, and competing with weeds. In general,
early growth is closely related to maturity date.
Early- to medium- maturing hybrids ( 102 to 114
days) tend to exhibit better early growth than do late
hybrids ( longer than 115 days). The best way to se-lect
hybrids with rapid early growth for North Caro-lina
is to contact Extension agents, seed company
representatives, and other organic growers who have
had experience with different corn hybrids.
Standability
Standability is an important measure of how well the
crop will stand under difficult environmental condi-tions.
Because pests affect stalk strength, an organic
hybrid needs to be able to resist lodging under stress.
Pest and disease resistance
Resistance to common seedling, leaf, and stalk dis-eases
is an important characteristic for hybrids in
organic production systems. Some hybrids even
tolerate insect pests such as European corn borer and
southern cornstalk borer. Growers should select hy-brids
that combine good early growth characteristics
with good resistance to diseases that are likely to be
problems in their fields.
Stress tolerance
Stress tolerance is the ability to produce acceptable
yield under drought or other environmental stresses.
Hybrid seed suppliers often refer to this characteris-tic
as “ drought tolerance.” This characteristic is im-portant
since limited available nitrogen, which is
often a problem in the early years of an organic sys-tem,
can lead to nutrient and drought stress. Hybrids
that can tolerate this stress will produce higher yields
and compete more successfully with weeds.
Yield
The only reliable indicators of yield potential in
organic systems will come from tests conducted
using organic practices. Most of the hybrid compari-
North Carolina Organic Grain Production Guide 7
sons done in organic systems use hybrids best suited
to the upper Midwest, and there is only a limited
amount of organic- yield test information available
in North Carolina. In these circumstances, grow-ers
may get the best information from local hybrid
comparisons when drought or other types of stress
were factors. For instance, official variety tests con-ducted
in North Carolina during 2002 reflect results
from drought conditions and might be indicators of
hybrid performance in organic systems. Those
hybrids with good compensating mechanisms may
do well in situations of low nitrogen availability
or high pest pressures. Growers should conduct
their own hybrid comparisons by selecting four to
six promising hybrids and evaluating them under
their own management practices. The best proce-dure
is the strip test, where each test hybrid is grown
adjacent to a standard hybrid ( see Figure 3- 1). This
pattern permits the yield data to be adjusted for
soil variability. If a standard is not used, test hy-brids
can be alternated with the hybrid that has
the best past performance. Growers conducting
their own hybrid evaluations should remember to
select uniform test fields to minimize soil vari-ability
and to restrict comparisons to hybrids of the
same maturity class.
Table 3- 1. Evaluations of organic and untreated corn hybrids for relative maturity, seed vigor, early growth rating,
standability, disease ratings, and stress tolerance.*
Relative Seed Early Standability Southern Corn Gray Stress
Hybrid Maturity Vigor Growth Rating Leaf Blight Leaf Spot Tolerance
Organic Hybrids
NC+ 69R36 115 8 6 7 6 5 7
NC+ 62N37 111 7 7 6 7 4 8
NC+ 68F32 112 7 6 6 7 4 7
NC+ 60N37 109 8 6 9 5 4 8
Doeblers N509 103 8 9 9 7 5 7
Doeblers N640 111 7 7 8 8 4 8
Untreated Conventional
Pioneer 34K77 107 7 6 6 7 4 7
Pioneer 34B97 108 6 6 6 6 5 7
Pioneer 3394 110 8 8 6 5 2 7
Pioneer 33G26 112 7 8 7 5 5 7
Pioneer 33M54 114 5 5 6 7 6 7
Pioneer 32R25 114 6 5 4 4 3 8
Syngenta N65- M7 109 5 6 6 4 6 8
Syngenta N79- L3 115 7 7 7 4 4 6
Augusta A- 4587 116 5 5 7 6 4 7
* Ratings are based on a scale of 1 to 10. A rating of 10 represents a plant with complete resistance or tolerance to dis-ease
or stress.
Figure 3- 1. Sample planting pattern for a strip test.
New Standard New Standard New Standard New Standard
Hybrid 1 Hybrid Hybrid 2 Hybrid Hybrid 3 Hybrid Hybrid 4 Hybrid
8 North Carolina Organic Grain Production Guide
Planting Date
Planting date is a crucial factor in the success of an
organic production system. Planting too early results
in slow growth and increases the amount of weed
competition, the incidence of seedling diseases, and
the likelihood of damage from seedling insects. On
the other hand, planting too late results in a greater
risk of drought stress, increased insect damage from
second and third generations of European corn bor-ers,
and reduced yield from a decrease in intercepted
sunlight due to decreasing hours of daylight. The
recommendations here attempt to balance these con-siderations.
In the tidewater and coastal plain,
plant organic corn between April 15 and May 15. In
the piedmont, plant organic corn between April 20
and May 20. In all locations, plant following at least
two days when average temperatures are above 65 º F.
Depending on the soil type, time soil preparation
and planting date so that soils are moderately dry at
planting to minimize the risk of seedling diseases.
Seedbed Preparation and Planting Depth
Seedbed preparation should begin with a major till-age
operation performed at least a month before
planting. If cover crops are used, they may need to
be killed and/ or incorporated into soils earlier than
one month before planting to allow for residue de-composition
and to avoid seed corn maggots. Heavy
applications of compost or manure should also be
incorporated earlier. Follow up with at least two
light tillage operations to create a smooth, weed- free
seedbed. The final tillage operation should be per-formed
on the day of planting to ensure that all ger-minated
weeds have been destroyed when the seed
is placed in the ground. The seed should be placed
exactly 1 inch deep, and the soil compressed to pro-vide
maximum seed- soil contact for rapid germina-tion
and growth. Seeding depth is a very important
factor in an organic production system. Seeds
planted too deeply will be slow to emerge, and seed-lings
will have immediate weed competition and a
greater likelihood of damage caused by seedling
diseases.
Plant Population
Plant population is another important factor in or-ganic
corn production, especially when corn is
grown on sandy soils. Plant populations should be
related to the moisture- holding capacities of each
individual field. In organic systems, corn plant
populations per acre should be 10 percent higher
than populations in conventional systems. The
higher plant population will increase light intercep-tion
and reduce weed competition and the effects of
pest damage. On soils with good- to- excellent water-holding
capacity, the goal is a stand of 30,000 to
33,000 plants per acre; on soils with average water-holding
capacity, 25,000 to 28,000 plants per acre;
and on soils with poor water- holding capacity, no
more than 22,000 plants per acre.
Row Spacing
Narrow rows permit more uniform plant distribution
and result in rapid closing of the canopy. In choosing
a row width, balance the potential advantages that
come from narrower rows against the additional
machinery cost and management that a narrow row
system demands. Because cultivation is the primary
weed control measure in organic production, make
row widths wide enough to permit the use of a trac-tor-
mounted cultivator. Where weeds are not a major
problem, use row spacing of 20 to 24 inches. Where
weed control will require multiple passes of a culti-vator,
use row spacing of 30 to 36 inches.
Soil Fertility
Corn generally requires from 120 to 160 pounds
of nitrogen per acre, 30 to 50 pounds of phospho-rus
per acre, 80 to 100 pounds of potassium per
North Carolina Organic Grain Production Guide 9
acre, and smaller amounts of sulfur and micronu-trients
to obtain optimum yield. Organic corn
growers should design their systems so that the
amount of nutrients added to the system offsets
the amount removed in the grain or forage. The
local offices of the USDA Natural Resources Con-servation
Service, the Cooperative Extension Ser-vice,
or the Soil and Water Conservation District
can provide guidelines for a nutrient management
plan. Chapter 6 in this manual also has more in-formation
on organic soil management.
Weed Management
Grassy weeds and warm- season broadleaf weeds,
such as cocklebur and morningglory, will be among
the most difficult to control. While tillage prior to
planting can help reduce early- season weeds, many
of the summer annuals will continue to germinate
and grow. It is very important to start with a clean
seedbed and to till the soil just prior to planting so
that the crop begins with a head start on new weed
seedlings. This will make it much easier to use culti-vation
to control grass and broadleaf weeds that are
smaller than the corn.
It is also important to take advantage of the
ability of the corn canopy to shade the soil. Shade
reduces the number of weeds germinating and
slows their growth. Use of increased plant popula-tions,
narrower rows, row directions perpendicu-lar
to the path of the sun, and tall- growing hybrids
all increase canopy density and lead to quick
canopy closure.
Remember that weed competition during the
first four to six weeks after planting will cause the
most damage in terms of yield reductions. Weeds
that emerge after canopy closure will have little
effect on yield, although they can make harvest
more difficult. Chapter 7 in this manual has more
information on managing weeds in organic pro-duction.
Insect Pest Management
Cultural practices are very important for estab-lishing
a vigorous, full corn stand. Stand estab-lishment
can greatly influence pest populations as
well as crop competitiveness and tolerance to pest
feeding. In fields where pests are historically at
high levels, do not plant organic corn if suitable,
effective, and economical pest management op-tions
are not available.
Crop rotation
Crop rotation is the most powerful tool for insect
management and is also often the lowest- cost
method of control. Rotations of at least two years
and use of a nongrass crop will reduce the levels of
many pests through starvation, interference with
insect reproduction, or both. Rotation also gives the
option of isolating corn crops from one year to the
next. Rotation in large units with a minimum of 800
to 1,000 feet between current and previous corn is
the most effective way to manage moderately mobile
pests such as billbugs.
Control of insects with tillage
Insect pests that feed on seed and small seedlings
are typically found in the soil or at the soil sur-face.
Populations of wireworms, cutworms, grubs,
seed corn beetle, and other pests can be reduced
with winter or early spring disking and the ac-companying
bird feeding and exposure. The com-bined
action of these factors can give meaningful
protection to planted seed and small seedlings. In
organic corn production, no- till should be avoided
or used with caution, especially in areas where
southern corn billbug, wireworms, and cutworms
are common.
Rapid germination and seedling grow- off
Rapid germination and seedling grow- off reduces the
time corn seed and seedlings spend in the most vul-nerable
stage between germination and the six- leaf
10 North Carolina Organic Grain Production Guide
stage and helps the crop gain a size advantage over
weeds. Losses to seedling insects and other pests can
be reduced by promoting early germination through
row- bedding, seeding at the recommended depth,
hybrid selection for performance under cool condi-tions,
and adequate soil fertility.
Crop maturity
In corn, timely maturity of the crop almost always
reduces insect damage. Certain pest insects and
pathogens ( for example, late- season corn borers
and fall army worms) reach high levels in late
July and August and may severely infest late-maturing
corn. Timely planting and avoidance of
late- maturing hybrids ( over 120 days) will reduce
the level of pests attracted to the crop in late- sea-son
and prevent yield loss. When planted early,
hybrids that mature in 112 days or less will usu-ally
avoid late- season caterpillar attack.
Hybrid selection
Rapid germination, early vigor, strong ear shanks,
tight husks, resistance to stalk rots and other
pests, strong stalks, and uniform performance
over a wide population range are factors influ-enced
by genetics that may reduce losses to in-sects.
Some hybrids have European- corn- borer-resistance
traits that will reduce susceptibility to
this important pest.
Major Corn Insect Pests and
Management
Corn billbugs
Billbugs can be serious pests of corn seedlings.
No insecticide approved for organic use has activ-ity
against billbugs. Combining cultural tactics—
rotation and isolation from previous corn crops—
along with rapid seedling emergence and grow- off
should help prevent concentrations of adult bill-bugs
and promote rapid accumulation of toler-ance.
Three additional billbug management tactics
are ( 1) avoiding areas with abundant nutsedge,
which is an alternative host for billbug; ( 2) avoid-ing
no- till production for organic corn because
no- till soils warm more slowly and delay germi-nation
and grow off; and ( 3) planting at the earli-est
possible date to allow seedling growth prior to
billbug adult emergence.
Wireworm and black cutworm
In organic systems, the major tactics for reducing
populations of these insects will be disc cultivation
and avoidance of no- till situations. Cultural methods
that promote rapid seedling growth and seeding at
adequately high populations to allow some seedling
loss can also be important.
European corn borer ( ECB) and southern corn-stalk
borer
Borers occur in all North Carolina corn fields. Their
populations fluctuate greatly between years and
sometimes within a single growing season. The or-ganic
farmer can influence the abundance of these
borers through rotation, site selection ( away from
first- generation ECB nursery areas in white potato
and wheat fields), early planting, use of short- season
corn hybrids, and selection of hybrids with ECB
tolerance. Taking these actions to manage both space
and time will help avoid high populations and pro-mote
tolerance for those borers that are present. Or-ganically
approved spinosad insecticides are labeled
for ECB on corn, but they are expensive and are not
likely to be effective when sprayed on tall corn. For
ECB scouting procedures and thresholds, consult
your county Extension office or the following Web
site: http:// www. ces. ncsu. edu/ plymouth/ pubs/ ent/
index1. html.
Western corn rootworm
Western corn rootworm is a pest only in nonrotated
corn. It can be successfully managed in an organic
system by rotating corn with other crops.
North Carolina Organic Grain Production Guide 11
Key Diseases and Management
Three key diseases— seed rots and seedling blights,
stalk rots, and charcoal rot, which are usually con-trolled
in conventional systems either by fungicides
or management practices— can have significant im-pacts
on organically grown corn. Growers should be
aware of these diseases and select hybrids and man-agement
practices that reduce the risk they pose.
While there are many other diseases that can attack
corn, they rarely cause economic loss. Pictures of
these field corn diseases can be found at this Web
site: http:// www. btny. purdue. edu/ Extension/ Pathol-ogy/
CropDiseases/ Corn/.
Seed rots and seedling blights
Seed rots and seedling blights caused by species of
Fusarium, Stenocarpella, Pythium, and other fungi
are often associated with the term “ damping- off.”
Plants die at emergence or within a few days of
emergence. These diseases are more prevalent in
poorly drained, excessively compacted, or cold, wet
soils. Planting old or poor quality seed with mechanical
injury will increase seed rot and seedling blight, as will
planting seed too deep in wet, heavy soils. Seed vigor
ratings are often used to select hybrids with genetic
resistance to seed rots and seedling blight.
Stalk rots
Stalk rots ( caused principally by the fungi
Stenocarpella zeae and species of Fusarium as well as
Colletotrichum graminicola) are present each year and
may cause considerable damage, particularly if abun-dant
rainfall occurs during the latter part of the growing
season. Stalks previously injured by cold, leaf diseases,
or insects are especially susceptible to attack by these
fungi. Diseased stalks ripen prematurely and are sub-ject
to excessive stalk breaking. Stalk rots not only add
to the cost of harvesting but also bring the ears in con-tact
with the ground, increasing their chance of rotting.
Adequate fertility ( particularly adequate potassium) is
the key to controlling stalk rot.
Charcoal rot
Charcoal rot ( caused by the fungus Macro- phomina
phaseolina) becomes most evident with the onset of
hot dry weather. It may cause stalk rot, stunting, and
death of the corn plant. This disease is often considered
to be stress related. Typically, when this disease occurs
in North Carolina, soil fertility and pH are at very low
levels. Although the fungus survives in the soil, rota-tion
is not generally helpful since most crops are sus-ceptible
to this disease. Supplying adequate nutrition
and water is the principal means of control. Hybrid
resistance in corn has not been documented.
Harvesting
Early harvesting usually avoids crop damage from
pests or hurricanes and prevents field losses re-sulting
from ear drop and fungal pathogens. Prob-ably
the most important reason for timely harvest
is the potential for yield reductions resulting from
ear loss and ear rots due to stalk lodging, ear
drops, and reductions in kernel weight. Fungal
diseases that infect the corn kernel also cause
more problems as harvest is delayed. Mycotoxins,
such as aflatoxin and fumonisin, which are pro-duced
by fungal pathogens, also increase as har-vest
is delayed and may result in corn that is un-suitable
for human or livestock consumption. Ide-ally,
corn harvest should begin as soon as the
grain reaches moisture levels of 25 percent or
less. Under favorable conditions, corn should be
ready to harvest in 10 days or less following the
black layer formation at the base of the kernels.
12 North Carolina Organic Grain Production Guide
Chapter 4. Crop Production
Management— Organic Wheat
and Small Grains
Randy Weisz, Crop Science Extension Specialist, NC State
University
John Van Duyn, Entomology Extension Specialist, NC State
University
Production Management
Key management practices for organic wheat and
small grain production:
• Choose varieties with resistance to disease and
insect pests.
• Plant on time ( not too early, not too late) in a
well- prepared seedbed.
• Implement crop rotation.
• Use correct drill calibration and operation.
• Avoid excessively high nitrogen levels ( but
work towards good soil fertility).
• Destroy crop residues with tillage, if possible.
Variety Selection
As a general rule, only small grain varieties that
have been successfully grown in the North Caro-lina
Small Grain Official Variety Test for two
years should be considered for production. Offi-cial
Variety Test reports are available online at
http:// www. smallgrains. ncsu. edu or from your
county Extension center. It is nearly impossible to
pick a single best variety. Consequently, produc-ers
should plant two or more varieties every sea-son
in order to reduce their risks and maximize
the potential for a high- yielding crop. The follow-ing
are general guidelines for selecting varieties
for organic wheat production:
• Check the Official Variety Test Report for a list
of varieties tested for at least two years.
• To avoid spring freeze injury, eliminate early-heading
varieties in favor of medium- and
late- heading varieties.
• If powdery mildew is common in your area,
select varieties that are rated as “ good” for
powdery mildew resistance.
• If you are a producer in the tidewater area,
select varieties that have “ good” or “ fair”
resistance to leaf rust.
• If possible, avoid varieties that are rated “ poor”
for Hessian fly biotype- L.
• If wheat is being produced for the baking in-dustry,
it is a good idea to check variety selec-tion
with the end user.
Planting Date
Not too early and not too late! Planting too early
puts the crop at severe risk for powdery mildew,
Hessian fly, aphids, and barley yellow dwarf virus.
Planting too late will reduce yields, increase the risk
of having a winter annual weed problem, and result
in thin stands that will attract cereal leaf beetles. For
the optimum planting times for your region, see the
most recent edition of the Small Grain Production
Guide or go online to http://
www. smallgrains. ncsu. edu/ Guide/ Chapter7. html.
Rotation and Field Selection
Planting wheat into old wheat stubble is always a
bad idea. Several major small grain diseases and
Hessian fly are vectored on old wheat stubble. Short
rotations put small grains at high risk to numerous
soilborne diseases and should be avoided in organic
production. Additionally, as described in more detail
below, the best way to avoid a Hessian fly problem
North Carolina Organic Grain Production Guide 13
is to plant at least one field ( or ¼ - mile) away from
last year’s wheat stubble and to avoid planting near
an early- planted wheat cover crop. Fields with a
history of Italian ryegrass, wild garlic, wheat spindle
streak, or wheat soilborne mosaic virus should be
avoided.
Drill Calibration and Operation
A good stand of wheat is the best defense against
weeds and cereal leaf beetle and is the best indicator
of a high yield potential. A complete guide to seed-ing
rate, drill calibration, planting depth, and other
planting considerations can be found in the most
recent edition of the Small Grain Production Guide
or go online to http:// www. smallgrains. ncsu. edu/
Guide/ Chapter6. html.
Soil Fertility
Wheat that yields 40 bushels per acre uses about 50
pounds of nitrogen per acre, 25 pounds of phosphate
per acre, and 15 pounds of potash per acre. Wheat is
a moderately heavy feeder, but not as heavy as corn.
For best yield results, an organically approved nitro-gen
source ( such as manure, compost, or a tilled- in
legume ) should be added at or before planting and
again in the spring. See Chapter 6 of this guide for
more information on soil fertility in organic produc-tion.
In early spring, it is possible to test a wheat
crop and determine how much additional nitrogen it
needs to produce optimal yield. Organic growers
may want to use tissue testing to determine whether
the crop needs additional spring top- dress nitrogen.
Weed Management
Essentially all weed control in organic wheat must
be achieved in seedbed preparation before planting.
Little to no cultivation is used in wheat after planting
to kill emerging weeds, but a rotary hoe or tine
weeder can be used before the crop emerges if
needed. However, weeds usually cause fewer prob-lems
in wheat than in corn or soybeans because
wheat is a strong competitor against weeds and is
drilled in narrow rows that quickly shade the soil.
Most wheat drills are set to plant rows that are 6 to 8
inches apart. Organic producers may want to take
advantage of row spacing as narrow as 4 inches to
help the wheat outcompete winter annual weeds.
Avoid planting organic wheat in fields with Italian
ryegrass or wild garlic problems as these weeds can
lead to quality problems in the harvested grain. Also,
use caution with hairy vetch as a cover crop in fields
where wheat will be planted because hairy vetch that
reseeds can contaminate wheat grain with seeds that
are similar in size and weight and that are difficult to
separate. See Chapter 7 for more information on
weed management in organic production systems.
Insect Pest Management
Wheat fields are susceptible to many kinds of in-sects.
Only a few species may become pests, and
even when they do, they usually do not reach dam-aging
above- threshold numbers. However, in some
seasons or under certain circumstances, insect pests
of wheat can be very damaging. The following in-sects
may become abundant enough to cause signifi-cant
injury to wheat crops in North Carolina: aphids
( several species), cereal leaf beetle, Hessian fly, and
armyworm ( sometimes called true armyworm).
Other plant- feeding insects, such as grasshoppers,
chinch bugs, or fall armyworms, may occasionally
damage wheat. Descriptions of all these insects may
be found in the most recent edition of the Small
Grains Production Guide, at county Extension cen-ters,
or at the following Web sites:
http:// www. ces. ncsu. edu/ plymouth/ pubs/ ent/ index4. html
http:// www. smallgrains. ncsu. edu/ Insects/ Insects. html
Wheat- feeding aphids
Three primary species of aphids occur in North
Carolina wheat: the English grain aphid, the bird- oat
cherry aphid, and the corn leaf aphid. Aphid feeding
14 North Carolina Organic Grain Production Guide
potentially reduces yield, but usually not dramati-cally.
Aphids are also vectors of barley yellow dwarf
virus ( BYDV), and this disease can be a serious con-cern.
A complex of biological control agents accom-panies
aphids, including parasites, predators, and
pathogens ( mainly fungi). These biological control
agents ordinarily exert a powerful controlling influ-ence
on aphid populations, especially in the spring,
although it usually requires some time before the
aphid populations “ crash” due to the combined influ-ence
of these agents.
Several cultural practices can help reduce the
chance of aphid damage and BYDV infection in
organic production:
Avoid early planting. Cool weather will slow
aphid feeding and activity in the newly emerged
crop. Planting after the end of warm weather not
only reduces the chance of crop damage due to
aphid feeding, but also makes it less likely that
aphid- transmitted BYDV infections will occur.
The aphid population may build up again in the
spring, but these populations are less damaging
because plants are larger, growing more rapidly,
and are more tolerant to feeding and BYDV infec-tion.
Avoid excessively high soil nitrogen levels.
Aphids reproduce most rapidly on plants with high-nitrogen
content. Maintaining nitrogen levels within
the prescribed agronomic level ( found in the most
recent edition of the Small Grain Production Guide)
helps to avoid high aphid populations.
Select wheat varieties with BYDV resistance. If
BYDV is a regular problem on your farm or on
neighboring farms, a highly effective strategy is to
select wheat varieties that are resistant to this dis-ease.
A list of wheat varieties and their resistance to
BYDV can be found at this Web site:
http:// www. smallgrains. ncsu. edu/ Varieties/
Varieties. html
Armyworm
Armyworm moths are one of a few moths active in late
winter and early spring. Armyworm caterpillars may
cause serious defoliation and substantial head drop.
They are most prevalent in the northeastern counties of
North Carolina.
Management options. Few cultural management
options are available for armyworm. Organic grow-ers
have the choice of accepting the feeding of army-worms
or using an insecticide approved for organic
production ( such as a spinosad) in emergency situa-tions.
Accepting the feeding of armyworm is not
likely to result in large yield losses unless plants
were defoliated early ( before or during the heading
period). For scouting information on armyworm,
check the most recent edition of the Small Grain
Production Guide or go online to http://
www. smallgrains. ncsu. edu/ Guide/ Chapter11. html.
Cereal leaf beetle
The cereal leaf beetle ( CLB) has one generation each
year, and both the adult and larval stages eat leaf
tissue on wheat and oats. They do not feed on barley,
triticale, or rye. Leaf feeding by larvae during April
and May can reduce yields.
Cereal leaf beetle is an introduced pest, and few
native biological control agents affect adult beetles,
eggs, or larvae. A few generalist predators, such as
lady beetles, appear to consume cereal leaf beetle
eggs and, perhaps, young larvae in early spring. The
North Carolina Department of Agriculture has re-leased
several species of exotic parasites throughout
the state. These parasites develop within cereal leaf
beetle eggs or larvae and have the potential to keep
populations below an economic level. Parasite re-lease
programs have worked well in several other
states, but so far have had limited success in North
Carolina.
Cultural practices. Cereal leaf beetles prefer to
attack a thin field full of little plants rather than a thick,
lush field full of large, healthy wheat. To minimize the
chances of beetle invasion, the organic producer needs
to do everything possible to assure a thick, well tillered,
healthy crop. This means good seed bed preparation,
planting on time, using high quality seed, correct drill
calibration, and getting good soil- seed contact at the
proper seeding depth. These steps will also increase the
crop’s tolerance to CLB feeding.
North Carolina Organic Grain Production Guide 15
Insecticides. Insecticides approved for organic
production ( such as a spinosad) and labeled for ce-real
leaf beetle may be applied in emergency situa-tions.
For scouting information for cereal leaf beetle,
check the most recent edition of the Small Grain
Production Guide or go online: http://
www. smallgrains. ncsu. edu/ Guide/ Chapter11. html.
In addition, a special publication on this pest can be
found at http:// www. ext. vt. edu/ pubs/ entomology/
444- 350/ 444- 350. html.
Hessian fly
In recent years, Hessian fly infestations have caused
extensive losses in many North Carolina fields. Or-ganic
farmers should use several methods to mini-mize
Hessian fly problems.
Rotation. Because the Hessian fly life cycle
depends largely upon the presence of wheat stubble,
using rotations that do not plant new wheat into or
near a previous wheat crop’s stubble will be the most
effective way to prevent infestations. Additionally,
since the Hessian fly is a weak flier, putting at least
one field ( or about ¼ - mile) between new wheat
plantings and the previous season’s wheat fields can
be a successful method of preventing new infesta-tions.
Tillage. Disking wheat stubble after harvest
effectively kills Hessian fly. Burning is not as effec-tive
as disking. Although burning wheat straw will
reduce populations, many pupae will survive below
the soil surface.
Careful use of cover crops. Serious Hessian fly
infestations have occurred in areas where wheat for
grain was planted near early- planted wheat for cover
or early- planted wheat for dove hunting purposes. In
organic systems using cover crops, selecting a small
grain other than wheat will reduce Hessian fly popu-lations.
Oats, rye, and triticale are not favorable for
Hessian fly reproduction and do not serve as a nurs-ery.
Plant on time. Do not delay planting until after
the first freeze ( often called the fly- free date) be-cause
an early freeze in North Carolina is not a de-pendable
event. Often a “ killing freeze” does not
occur until December in many areas of North Caro-lina,
which is later than most growers need to have
wheat planted for agronomic purposes. Organic pro-ducers
throughout North Carolina should also avoid
planting before the recommended planting dates.
Resistant varieties. Many wheat varieties are
advertised as having Hessian fly resistance. To be
effective in North Carolina, however, wheat varieties
must be specifically resistant to Hessian fly biotype-
L. A list of wheat varieties with biotype- L resistance
can be found on the Internet at http://
www. smallgrains. ncsu. edu/ or through county Ex-tension
offices. For more information on Hessian
Fly, see The Hessian Fly: A Pest of Wheat in North
Carolina ( AG- 368), which is available online:
http:// www. ces. ncsu. edu/ depts/ ent/ notes/ Grain/ Hes-sian/
HflyAG- 368. html.
Disease Management
Disease identification
The first step in solving disease problems is to iden-tify
the disease. Excellent small grain disease infor-mation
and assistance with disease identification can
be found in the latest edition of the Small Grains
Production Guide or on the Web at http://
www. smallgrains. ncsu. edu/ Diseases/ Diseases. html.
Varieties are rated for disease resistance at http://
www. smallgrains. ncsu. edu/ Varieties/ Varieties. html.
Barley yellow dwarf virus
Barley yellow dwarf virus ( BYDV) is the most im-portant
viral disease of wheat, oats, barley, and rye
in this state. The virus is transmitted by aphids that
spent the summer on nearby corn crops or host
grasses. The best control measure in organic produc-tion
is to plant varieties that are resistant to this dis-ease.
Powdery mildew
One of the most yield- limiting factors in North Caro-lina
wheat production is powdery mildew. This is
especially true in the coastal plain, the southern pied-mont,
and some tidewater areas. Conventional pro-
16 North Carolina Organic Grain Production Guide
ducers often do not consider powdery mildew in
their planning because they can rely on foliar fungi-cides
to control the disease if it occurs. Organic pro-ducers
do not have that luxury.
Select resistant varieties. The best protection
against powdery mildew is to select wheat varieties
that are resistant to it. Organic producers who want
high- yielding wheat must plant powdery- mildew-resistant
varieties. Wheat varieties grown in North
Carolina are evaluated for disease resistance every
year, and new disease- resistance ratings are pub-lished
in the Small Grains Official Variety Test Re-sults
and posted on the Internet every July in time
for growers to order the best varieties for the next
year’s production. Organic producers should check
the Web site http:// www. smallgrains. ncsu. edu/ Variet-ies/
Varieties. html every year ( or contact the county
Extension agent for the information) and use the list
of the most resistant varieties as a starting point for
ordering seed.
Adjust planting date. A second defense against
powdery mildew is to plant after the weather has
turned cold. This decision involves a trade- off. Al-though
powdery mildew does not grow in cold
weather, neither does wheat. This means that late-planted
wheat may avoid powdery mildew, but it is
also likely to suffer from lower yields and attack by
cereal leaf beetle. However, organic producers, espe-cially
those in the coastal plain, southern piedmont,
and tidewater region, should also avoid planting
before the recommended planting dates.
Leaf rust
Leaf rust is a foliar disease that attacks wheat late in
the growing season. While leaf rust can occur any-where
in North Carolina, it is most likely to be a
problem in the tidewater. Conventional producers
rely on foliar fungicides to protect the crop from this
disease. Organic producers must select varieties with
good resistance to leaf rust. Organic producers, espe-cially
those in the tidewater, should try to select vari-eties
that have a combination of powdery mildew
and leaf rust resistance. Variety resistance to leaf rust
also deteriorates from year to year, so organic pro-ducers
should check the most recent variety ratings
every year before ordering seed.
Loose smut
Loose smut symptoms occur between heading and
maturity. Infected seed appears normal. The fungus,
which is found inside the embryo of the seed, will
grow within the plant from germination until the
seed heads emerge and smutted grains appear. There-fore,
symptoms from an infection that occurs in one
year will not be seen until plants from the infected
seed mature in another year. Because loose smut is
seedborne, control measures focus on the seed to be
planted. Certified seed fields are inspected for loose
smut, and strict standards are enforced. Seed from
fields with loose smut are rejected. Therefore, using
certified seed is a highly effective way to avoid loose
smut. Organic producers who use farmer- saved seed
should never plant seed from a crop infected with
loose smut.
Septoria leaf and glume blotch
Septoria leaf and glume blotch may occur at any
time during the growth of the plant and on any por-tion
of the plant. Rotation away from small grains
for at least three years can lessen the severity of
septoria. Plowing under wheat stubble will prevent
infection from the previous wheat crop. Potash, cop-per,
and magnesium should be kept at recommended
levels. In some cases, septoria can be seedborne, so
certified seed can reduce introduction of the disease.
Organic farmers should never save seed for planting
if the wheat was infected with septoria.
Scab or head blight
Scab, a fungus that is seen as prematurely bleached
heads or spikelets, can occur in all small grains. Of
the small grains, wheat and barley are the most sus-ceptible
to this disease, and rye and triticale are the
most resistant. Scab occurs and is spread to small
grains in the spring. It also results in toxins
( vomitoxin is most common) in the harvested grain.
The first line of defense against scab is to plant
wheat varieties with resistance to the fungus. A com-
North Carolina Organic Grain Production Guide 17
plete list of wheat varieties and their resistance to
head scab can be found at http:// www. smallgrains.
ncsu. edu or at county Extension centers. Wheat pro-ducers
with a history of scab should seriously con-sider
selecting varieties based on this information.
Tillage practices that bury wheat or corn residues
and rotations of at least three years are effective
means of controlling scab in organic production.
Planting several wheat varieties with different head-ing
dates will stagger head emergence and flowering
through the spring and reduce the chance that envi-ronmental
conditions will be suitable to scab in all
wheat fields.
If scab is present, the combine may be adjusted
so that the lightweight diseased grain is removed
along with the chaff. This will not remove all the
infected grain, but can help reduce mycotoxin levels
in the grain going to market. Organic producers
should never use farmer- saved seed if head scab was
present in the crop that produced the seed.
Other small grain diseases
Several other diseases can be problems for small
grain in North Carolina. Growers in need of more
detailed information should check online at http://
www. smallgrains. ncsu. edu or with their county Ex-tension
agent.
Avoiding Spring Freeze Injury
Late spring freeze damage is a major factor in reduc-ing
yields of North Carolina wheat. “ Heading date”
is an important indication of how susceptible a vari-ety
will be to late spring freeze damage. Early- head-ing
varieties are the most susceptible to freeze dam-age.
Medium- and late- heading varieties are more
likely to avoid spring freeze damage, and they gener-ally
produce higher yields than early- or medium-early
heading varieties. Heading date also indicates
the best planting date for a wheat variety. Medium-and
late- heading wheat varieties tend to do best
when planted at the start of the planting season, and
should be the first varieties planted. Early and me-dium-
early varieties tend to produce the highest
yields when planted later in the fall. Wheat variety
heading date information can be found online: http://
www. smallgrains. ncsu. edu/ Varieties/ Varieties. html.
18 North Carolina Organic Grain Production Guide
Chapter 5. Crop Production
Management— Organic Soybeans
Jim Dunphy, Crop Science Extension Specialist, NC State University
John Van Duyn, Entomology Extension Specialist, NC State University
Production Management
Key management practices for organic soybean pro-duction:
• Choose varieties that perform well in your area
( selecting earlier or mid- season maturity
groups, if possible).
• Plant on time ( not too late).
• Adjust equipment for a high plant population.
• Rotate crops.
• Plant in narrow rows.
Variety Selection
Choosing a soybean variety also means choosing a
Maturity Group. In organic production, an earlier-maturing
( Maturity Group V for most of North Caro-lina)
or mid- season variety ( Maturity Group VI) is
preferred over late- maturing varieties ( Group VII or
later). Early- maturing beans can avoid hurricane
winds and moisture and associated disease problems
and yield losses. Because of soil type and more fre-quent
rains, the blacklands of North Carolina can use
an earlier- maturing bean ( Group V or earlier) without
yield loss. However, farther west and on sandier soils, a
later- maturing variety ( Group VI or later) may be
needed to get adequate yields. In the coastal plain, a
Group VI or late V ( or an earlier planting) will help
avoid corn earworm ( CEW) infestation during flower-ing.
CEW is seldom a problem in the piedmont. Variety
selection is also an excellent way to deal with nema-tode
problems. Selecting varieties that are resistant to
the species and race of nematode present in the field
can limit the yield loss caused by these pests. It is also
a good idea to choose at least two different varieties in
order spread out the seasonal workload and risk. The
Official Variety Test Report available at
www. ovt. ncsu. edu or through your county Extension
center is a good source of information on varieties.
Unfortunately, there are fewer and fewer conven-tional
or nontransgenic varieties available on the
market. Organic farmers must be aware that
transgenic beans are not allowed in certified organic
production, and choose alternate varieties. Table 5- 1
lists top- yielding non- GMO, feed- grade varieties in
North Carolina through 2004, as noted by J. Dunphy
in North Carolina Soybean Variety Information
( 2005, Extension publication CS- SB- 15).
Planting Date
Planting date and variety ( or maturity group) selection
go hand- in- hand. The key is to match planting date and
variety maturity to the soil so that the row middles are
lapped with soybean plants about 3 feet tall by flower-ing
time. Planting earlier or planting a later- maturing
variety can improve the likelihood of achieving this. In
an organic farming system, avoiding pest problems is
an important management technique. Planting early ( by
the end of May) with an early to mid- season variety
can help the crop avoid insect and disease problems.
Row Spacing
Soybeans in row widths of 20- inches or less tend to
have higher yields than soybeans in wider row
widths. Narrow- row soybeans also lap the row
middles sooner, making further weed control mea-sures
during the season unnecessary.
Plant Population
Weeds are the main pest that organic soybean pro-ducers
are going to face, and a thick plant population
North Carolina Organic Grain Production Guide 19
will compete with weeds more effectively. Thicker
populations have denser, earlier- closing canopies
that out- compete weeds and do not allow enough
light to penetrate for weed seed germination. How-ever,
a thick plant stand also traps moisture in the
canopy, which creates a good environment for dis-ease.
A good compromise is needed, but a closed
canopy is preferred. Although it increases the risk of
disease, it is also the best way to maximize yields.
An ideal stand would have plants that are about 3
feet tall with row middles lapped by the time of
flowering. Plant population in the field can vary
widely and still achieve good yields. On 36- inch
rows with a May planting date, an ideal plant popu-lation
would be 6 to 8 plants per foot ( about 100,000
plants per acre). In 20- inch rows, the recommended
plant population is still 100,000 plants per acre, but
the plant population per foot will be lower. If plant-ing
on 7- inch rows, 2 plants per foot ( 150,000 plants
per acre) can achieve good yields. Seeding rate will
depend on the planter calibration, seed germination,
and soil condition. Proper calibration of the planter
is important, as well as planting in ideal soil condi-tions
( the soil should be warm and moist, but not
wet). If planting in June, increase these seeding rates
by 20 percent.
Soil Fertility
Soybeans yielding 50 bushels per acre will remove
about 188 pounds of nitrogen per acre, 41 pounds of
phosphate per acre, and 74 pounds of potash per acre
from the soil. However, manure and compost appli-cations
are usually unnecessary because soybeans
are nitrogen- fixing legumes and the crop can make
use of any nutrients applied to, but not removed by,
previous crops. If soybeans were not grown in previ-ous
years, soybeans should be inoculated with spe-cies
of Bradyrhizobium bacteria specific for soy-beans.
Inoculums must not be genetically engi-neered.
See Chapter 6 of this guide for more infor-mation
about organic soil management.
Table 5- 1. Nontransgenic soybean varieties, relative
yield over all locations, number of locations and years
in variety trial.
Percent +/- No. First Last
Variety Average* of sites year year
Maturity Group IV
DP 4748 S - 13.0 2 2000 2000
Maturity Group V
5002T - 2.9 6 2003 2004
5601T - 3.1 13 2001 2004
95B33 - 5.1 14 2000 2001
AP 572STS - 8.9 8 2000 2000
Bolivar - 2.3 4 2004 2004
DP 5110 S - 6.3 22 2000 2004
DP 5989 - 4.0 22 2000 2002
Fowler - 3.5 28 2000 2004
Freedom - 16.2 4 2004 2004
HBK C5894 - 3.1 4 2004 2004
Hutcheson - 4.3 35 2000 2004
Ozark - 11.8 4 2004 2004
SS 5200- STS - 17.0 16 2001 2003
SS 597 2.4 15 2000 2001
Teejay 8.4 4 2004 2004
USG 550nSTS - 14.0 13 2002 2004
Maturity Group VI
665 6.4 25 2000 2003
Boggs - 13.0 8 2004 2004
Dillon 2.5 29 2000 2004
HBK 6600 - 8.0 8 2000 2000
NC- Roy 9.7 29 2000 2004
Satelite - 9.7 22 2000 2002
Soyola - 0.1 25 2000 2003
Maturity Groups VII and VIII
Cook 3.8 15 2000 2004
N7001 0.6 18 2000 2004
N7102 - 21.5 4 2002 2002
N7103 - 8.7 8 2000 2002
NC- Raleigh 12.1 18 2000 2004
* Percent above (+) or below (-) average yield of all varieties of the
same maturity group at the same locations in NC Official Variety
Tests ( OVT) in 2000 through 2004.
20 North Carolina Organic Grain Production Guide
Weed Management
Organic weed management is more challenging in
soybeans than in corn since the soybean foliage does
not generally overlap and shade the row middles until
later in the season. Generally, narrow rows and in-creased
plant population can help the crop compete
more effectively against weeds. When managing weeds
in soybeans, consider also that different planting times
for soybeans result in the plants competing against
different sets of weed species. Weeds that emerge dur-ing
the first four to five weeks after planting will cause
the most damage in terms of yield reductions. Weeds
that emerge after this time will have little effect on
yield, although they may make harvest more difficult
and will set seed. The goal should be to keep the field
clean through the first four to five weeks after planting.
See Chapter 7 of this guide for more information on
managing weeds in organic production.
Insect Pest Management
Differences caused by variety selection, planting
date, cultural techniques, site, and season cause great
variations in soybean plant attractiveness to insect
pests. If organic soybean farmers recognize these
differences, they can manage the crop for reduced
insect pest numbers or, when this is not possible,
predict which fields are attractive and may need
more attention to prevent yield loss. The organic
soybean grower can normally rely on three factors to
limit insect damage: reducing soybean attractiveness
to pests, beneficial insects that reduce pest numbers,
and the plant’s ability to compensate for insect dam-age
( tolerance). Important tactics used to reduce
insect damage include the following five strategies:
Rotation
Rotation helps reduce levels of pests like soybean
colaspis and cyst nematode and often improves crop
health. Avoiding pests through rotation of at least two
years allows soybeans to tolerate the feeding of pests
that later move into the field.
Soil fertility and pH maintenance
Thin plant stands often have more corn earworms,
but good growth reduces attractiveness. Reducing
plant stress from low pH, poor fertility, or inadequate
moisture will enable plants to better tolerate insect
feeding.
Variety selection and early planting
High caterpillar populations can often be avoided by
early planting of an early- maturing variety ( such as
varieties from Maturity Groups III, IV, or V). These
plantings will bloom and harden- off before the corn
earworm moth flight from corn fields, and the plants
will be unattractive to the moths. Also, early matu-rity
can greatly reduce soybean looper, velvetbean
caterpillar, and late stink bug infestations. In rare
situations, stink bugs can be trap- cropped by early-maturity
fields, leading to greater damage.
Narrow rows
A complete canopy allows a higher level of biologi-cal
control by insect predators, parasites, and dis-eases.
Also, narrow- row soybeans seem to be less
attractive to egg- laying corn earworm moths.
Remedial control
Group V or later- maturing varieties that are planted
after late May can become infested by corn earworm
moths moving from corn. These moths produce pod-feeding
corn earworm larvae, and a high infestation
may reduce yield by as much as 50 percent. Also,
populations of leaf- feeding caterpillars ( green
cloverworm, soybean looper, and velvetbean cater-pillar)
may occasionally damage soybeans to above
threshold levels. These worms are usually very late-season
pests. In instances where caterpillar pests are
not avoidable, insecticides approved for organic
production, such as spinosads or Bacillus
thuringiensis ( Bt), may be successfully used. Scout-ing
and the use of thresholds will indicate which
fields are at risk. For scouting procedures for corn
earworm see this Web site: http:// www. ces. ncsu. edu/
plymouth/ pubs/ ent/ index3. html.
North Carolina Organic Grain Production Guide 21
Disease Management
Soybeans have very few disease problems. This
makes disease management in organic soybeans
relatively easy. Nematodes are the main soybean
disease agent in North Carolina. However, Asian
soybean rust is a possible problem, and, if
present, will require much more intensive man-agement
to make organic soybean production vi-able.
Nematodes
The best way to avoid nematode damage is to plant
varieties that are resistant to the nematode ( and race)
present in the field. These varieties can be found on
the Web site www. soybeans. ncsu. edu/ soyvar or from
county Extension agents. Conventional nematicides
are prohibited in organic agriculture. Crop rotation
of at least two years will probably help reduce soy-bean
cyst nematode populations, but is not as useful
when dealing with root knot nematode because it has
multiple host plants. If nematode damage is sus-pected,
collect samples from the field ( fall is the best
time) and send them to the NCDA& CS laboratory
( 1040 Mail Service Center, Raleigh, NC 27699-
1040, 919- 733- 2655) for nematode assays. They will
identify a nematode population and species, if it is
present. The Agronomic Division of NCDA& CS
also has nematode management and assay informa-tion
on their Web site: www. ncagr. com/ agronomi/
nemhome. htm.
Asian soybean rust
Asian soybean rust is a disease that has the potential
for causing severe economic damage in North Caro-lina
soybean crops. It must be considered when man-aging
for soybean disease. To manage soybean rust
potential in organic soybeans in North Carolina,
select early- maturity groups and/ or plant early to get
the plants out of the fields in time to avoid the rust
inoculum. Do not, however, create such an early-maturing
soybean crop that yields are reduced sub-stantially.
For more information on soybean rust, go to one
of these Web sites:
• www. usda. gov/ soybeanrust/ ( USDA site on
Asian soybean rust)
• www. ces. ncsu. edu/ depts/ pp/ soybeanrust/ ( Soy-bean
Rust Forecast Center at NC State Uni-versity)
• www. sbrusa. net ( USDA online soybean rust
tracking site)
• www. attra. ncat. org/ attra- pub/
asian_ soy_ rust. html ( Appropriate Technology
Transfer for Rural Areas document on pos-sible
organic treatments for Asian soybean
rust)
22 North Carolina Organic Grain Production Guide
Chapter 6. Soil Management
Carl Crozier, Soil Science Extension Specialist, NC State University
Keith Baldwin, Extension Specialist, NC A& T State University
David Howle, Assistant Professor, Clemson University
Soil Management and the Organic
Standards
In an organic farming system, rotation and tillage
practices must provide an appropriate seedbed and
pest control while minimizing erosion. Soil fertility
must be sustainable without application of prohib-ited
substances. Soil management practices must be
developed in consultation with the certifying agent
who judges compliance with organic standards, ap-proves
inputs, and specifies needed documentation.
Crop Rotation, Tilth, Fertility, and Pest
Management
Crop rotation is critical to the maintenance of soil
tilth ( physical condition), fertility, organic matter,
and as a preventive practice to minimize pest prob-lems.
No specific rotations are mandated, but sug-gested
crops to include are sods, cover crops, green
manures, and catch crops. The rotation adopted must
resolve any relevant problems with soil organic mat-ter
content, deficient or excess plant nutrients, soil
erosion, and pest management. Defining a rotation is
also a key component in designing soil sampling and
tillage management schemes. For short rotations
( two to three years), soil samples can be collected
once per rotation. For longer rotations, soil samples
may still need to be collected every two to three
years, preferably prior to planting the most inten-sively
managed crops.
Soil Fertility Management
Although crop nutritional requirements are the same
for organic and conventional farms, organic producers
need to be more creative due to the limitations on al-lowable
inputs. Soils throughout the Carolinas differ in
texture, organic matter, past erosion, and residual nutri-ent
contents. Periodic soil testing is the only way to
understand the current fertility level and maintain the
fertility status of each field. Plant tissue analysis can
also be used to verify soil fertility status, particularly
for nutrients not easily measured in routine soil tests
( nitrogen, sulfur, boron). With tissue testing, the appro-priate
plant part must be collected at the proper growth
stage as specified by laboratory guidelines ( see
www. ncagr. com/ agronomi/ ptaflyer. htm or contact your
county Extension center).
North and South Carolina have numerous sources
of plant and animal manures and by- products. This
region also has a favorable climate for growing a diver-sity
of rotational and green manure cover crops that can
provide needed nitrogen and other nutrients. Farmers
should study their crops to fully understand production
requirements, nutrient needs, and common production
problems. Crops differ in their nutrient removal rates
( Table 6- 1), and nutrient sources differ in their nutrient
contents ( Table 6- 2).
Certain inputs are allowable on organic farming
systems, if applied according to guidelines. These in-clude
mostly natural and a few synthetic materials. The
National List of Allowed and Prohibited Substances
under the National Organic Program is available
online: http:// www. ams. usda. gov/ nop/ NationalList/
FinalRule. html. This list specifies synthetic substances
allowed for use and nonsynthetic substances prohibited
for use in crop production. The Organic Materials Re-view
Institute ( OMRI) was developed to review mate-rials
for approval in order to simplify the National List.
OMRI classifies materials as either allowed ( A) or
regulated ( R), and lists generic and brand names of
materials. OMRI can be accessed via the Web at
www. omri. org; or by mail or phone at Box 11558,
North Carolina Organic Grain Production Guide 23
Table 6- 1. Nutrient removal ( in pounds) by different crops. Missing values
indicate no data available.
Corn Sorghum- Irish Tobacco
Nutrient grain Soybean Fescue Ryegrass Sudan Potato ( flue- cured)
N 112 188 135 215 319 90 85
P 2 O 5 53 41 65 85 122 48 15
K 2 O 40 74 185 240 467 158 155
S 10 23 20 - - 7 12
Ca 2 10 - - - 5 75
Mg 8 10 13 40 47 7 15
B 0.03 - - - - - -
Cu 0.06 0.05 - - - - 0.03
Zn 0.15 0.05 - - - 0.08 0.07
Yield 150 bu 50 bu 3.5 tons 5 tons 8 tons 15 tons 3,000 lbs
Table 6- 2. Nutrient content of selected natural sources. These are general values and may not accurately repre-sent
the content of any specific source. Laboratory analysis should be performed prior to utilizing these materi-als.
Missing values indicate no data. Use of any specific source should be approved by the certifying authority
prior to submitting an application for organic certification.
Source Units N a P 2 O 5 K 2 O S Ca Mg B Cu Mn Zn
Swine lagoon lb/ acre 109b 37.1c 93.1c 10 26 8.3 0.18 0.3 0.34 1.5
liquid in/ acre 68c
Broiler, fresh
manure lb/ ton 15.6 17 11 2 10 4 - - - -
Broiler,
stockpiled litter lb/ ton 21.6 80 34 12 54 8 0.04 0.27 0.59 0.55
Turkey,
fresh manure lb/ ton 16.2 25 12 - 27 2 - - - -
Turkey,
stockpiled litter lb/ ton 21.6 72 33 9.5 42 6.8 0.05 0.34 0.62 0.56
Blood, dried lb/ ton 240 to 60 - - 6 - - - -
300 ( total N)
Bone meal, raw lb/ ton 70 ( total N) 440 - 4 440 12 - - - -
Shrimp process
waste lb/ ton 58 ( total N) 200 - - - - - - - -
Cotton motes lb/ ton 40 ( total N) 10 60 12 80 14 - - - -
Peanut hull meal lb/ ton 24 ( total N) 12 16 - - - - - - -
Wood ash lb/ ton 0.0 40 120 - 400 20 - - - -
a Plant- available N unless otherwise stated.
b Plant- available N values shown represent estimate for material incorporated into the soil unless specified otherwise.
c Sprinkle- irrigated and not incorporated.
Eugene, OR 97440, ( 541) 343- 7600. Other materials
should be considered prohibited until further notice. In
all cases, input use should be included in the farm plan
and confirmed by the certifying authority prior to sub-mitting
an application for certification as an organic
farm.
Critical aspects of soil fertility management in-clude
pH, major nutrients ( nitrogen, phosphorus, potas-sium),
secondary nutrients ( sulfur, calcium, magne-sium),
and micronutrients ( especially boron, copper,
manganese, and zinc; but also iron, molybdenum, chlo-rine,
selenium, and cobalt). A summary of soil fertility
24 North Carolina Organic Grain Production Guide
1 Inputs are limited to materials approved on the National Organic Program List or on the OMRI- approved source list after consultation with the certifying agent regarding need to docu-ment
deficiency and application records.
2 Avoid over- application of micronutrients since toxicities can occur.
3 See restrictions in text.
4 Documentation of nutrient deficiency required.
5 Deficiencies of Co, Mo, and Se are not common in North Carolina, and these elements are not included in routine tissue analysis performed by the NCDA& CS. Consult a Cooperative
Extension office for information regarding private agricultural laboratories.
Cobalt ( Co), Iron ( Fe), Molybdenum ( Mo),
Selenium ( Se)
Manures, animal and plant by- products, sulfates, car-bonates,
oxides, or silicates4
Chlorides, nitrates
Table 6- 3. Soil fertility management options.
Problem
Effect on Plants Documentation Supply Options1 Not Allowed
Secondary Nutrients
Magnesium ( Mg)
Boron ( B)
Copper ( Cu)
Hydrated or burnt lime
[ Ca( OH) 2 , CaO]
Synthetic fertilizers
Lime ( standard, ground calcitic or dolomitic carbonate
source)
Dolomitic lime, Epsom salts ( MgSO 4 ) 4, sulfate of potash
magnesium, bone meal, plant by- products ( cottonseed
meal, wood ash)
Manures, animal and plant by- products,
soluble boron fertilizers4
Manures, animal and plant by- products,
sulfates & oxides4
Soil test
Soil test, tissue
analysis
Tissue analysis
Soil test, tissue
analysis
Nutrient solubility,
root development,
microbial activity
Component of chlorophyll, cell
pH and cation balance, en-zyme
activation
Cell wall & membrane stabili-zation,
cell growth, carbohy-drate
& protein metabolism,
pollen germination
Enzyme component, photosyn-thesis,
respiration, cell wall
lignification, pollen formation
pH
Sulfur ( S) Synthetic fertilizers
Tissue analysis
Component of proteins; volatile
compounds of mustard, garlic,
onion
Calcium ( Ca) Ca( OH) 2 , CaO, calcium
nitrate [ Ca( NO 3 ) 2 ]
Lime ( mined carbonates), gypsum ( CaSO 4 ), bone
meal, ash
Soil test, tissue
analysis
Cell wall & membrane stabiliza-tion,
cell growth, osmoregulation
Manures3, plant by- products ( cotton motes, peanut meal),
elemental sulfur4, gypsum ( CaSO 4 ), Epsom salt ( MgSO 4 ) 4,
sulfate of potash ( K 2 SO 4 ) 4
Chlorides
Manganese ( Mn) Soil test, tissue
analysis
Manures, animal and plant by- products, sulfates &
oxides4
Chlorides
Zinc ( Zn)
Enzyme activation, protein
component, photosynthesis,
cell growth
Enzyme component & activa-tion,
protein synthesis
Soil test, tissue
analysis
Manures, animal and plant by- products,
sulfates & oxides4
Chlorides
Tissue analysis5
Major Nutrients
Nitrogen ( N) Synthetic fertilizers, sew-age
sludges, municipal
waste composts
N fixation by legumes, manures3, animal by- products
( blood, fish), plant by- products such as cotton ( re-stricted
due to pesticide use) or apple fermentation
wastes, mined sodium nitrate ( NaNO 3 ) 3
Component of proteins, Tissue analysis
chlorophyll
Phosphorus ( P) Processed rock phos-phates
Manures3, rock phosphate, animal by- products ( bone meal;
fish, shrimp, & oyster scraps; leather)
Soil test, tissue
analysis
Component of nucleic
acids
Potassium ( K) Manures3, plant by- products ( ash, dried seaweed), green- KCl if excess chloride
sand, sulfate of potash ( K 2 SO 4 ) 4, possibly muriate of potash
( KCl) 3,4
Soil test, tissue
analysis
Water, salt, & pH balance;
enzyme activation; protein
synthesis; photosynthesis
Micronutrients2
North Carolina Organic Grain Production Guide 25
parameters and organic management options is given in
Table 6- 3.
Soil pH is important because it influences nutri-ent
solubility, microbial activity, and root growth.
The low pH levels common in native Carolina soils
continue to be the most common limiting factor for
plant development seen in samples submitted to the
NCDA& CS Agronomic Division Laboratory. Since
most agricultural lime is from naturally- occurring
minerals of relatively low solubility, its use is gener-ally
allowed in organic farming systems. Hydrated
limes and burnt limes are not allowed. Pelletizing
agents should be evaluated to determine that they
are not prohibited materials.
Nitrogen ( N) is the most frequently limiting nutri-ent
for crop production. Organic farms need to supply
N through sources such as legumes, animal wastes or
by- products, plant- processing by- products, or limited
additions of mined mineral deposits. It is possible for a
nitrogen- fixing legume or legume- and- grass mixture
cover crop to provide adequate nitrogen for certain
cash crops. A seed inoculum is recommended for le-gumes
unless adequate native inoculum is present, and
adequate soil fertility is needed to ensure no other fac-tors
limit legume growth. Inoculums, however, must
not be genetically engineered. Nitrogen- fixing cover
crops for summer in North Carolina include cowpeas
and soybeans. Winter N- fixing cover crops include
hairy vetch, Cahaba vetch, Austrian winter peas, and
many clovers. Many farmers in North Carolina use
composted or uncomposted poultry litter to supply the
nitrogen needs for their organic field crops. Poultry
litter and poultry by- products are available in many
parts of the state. Mined nitrates, such as sodium nitrate
( NaNO 3 , bulldog soda, or Chilean nitrate) may be used,
but are limited to a maximum of 20 percent of the
crop’s total N requirement. Constantly relying upon
NaNO 3 , a restricted substance in organic agriculture,
will be questioned by a certification agency.
Other nutrients. Phosphorus, potassium, calcium,
magnesium, sulfur, copper, manganese, and zinc can
generally be supplied in adequate amounts through
additions of lime ( calcium, magnesium), animal or
plant by- products or wastes ( phosphorus, potassium,
sulfur, micronutrients), or permissible mineral inputs.
Naturally occurring minerals of relatively low solubil-ity
are generally allowed ( lime, gypsum, rock phos-phate,
rock dusts, mined humates).
In addition, the following naturally occurring
minerals of relatively high solubility may be applied
if used in compliance with the National List:
• Magnesium sulfate ( Epsom salt), with a docu-mented
soil deficiency.
• Sulfate of potash and potassium magnesium
sulfate, if from an approved source and with a
documented soil deficiency.
• Muriate of potash, if derived from a mined
source and applied in a manner that mini-mizes
chloride accumulation in the soil. This
may be acceptable for most crops in the Caro-linas
with a soil test to document the defi-ciency
and recommend an application rate.
• Many micronutrient salts, with documented
soil deficiency and if not in the form of nitrate
or chloride salts. This includes various soluble
boron products and sulfates, carbonates, ox-ides,
or silicates of zinc, copper, iron, molyb-denum,
selenium, and cobalt.
Numerous animal and plant by- products are
available to provide essential crop nutrients ( Table 6-
2). It is important to check with the certifying
agency before using any input.
Tillage Practices
Management of soil tilth, organic matter, and fertility is
an important aspect of a successful organic farming
system. Current organic systems usually require tillage
prior to planting and cultivation after planting, espe-cially
for corn and soybean production, to control
weeds and reduce the incidence of seedling diseases
and insect pests. However, tillage destroys the organic
matter that is critical in improving soil fertility and soil
water- holding capacity. The use of rotations with cover
crops where the soil surface is covered with a growing
crop for most of the year is important in maintaining
organic matter content during periods when corn is not
grown. Tillage should be performed when soil moisture
26 North Carolina Organic Grain Production Guide
is low enough to prevent compaction. Since primary
tillage operations are usually performed at least a
month before a crop is planted, this requires careful
planning and the ability to take advantage of periods of
dry weather. No- till agriculture in organic systems is
starting to be used in parts of the country. The Rodale
Institute has experimented with no- till organic using
cover crops and tractor- mounted rollers to kill the
cover just before planting into it.
Documenting Crop Nutrient Deficiencies
and Soil Quality Maintenance
Since use of some soil amendments is limited to cases
of nutrient deficiency, organic producers should main-tain
records of soil test results and plant tissue analysis
to document specific nutrient deficiencies that need
correction. Soil test records can also be useful in docu-menting
soil quality maintenance because they will
show changes in humic matter and nutrient levels over
time. It is important to avoid topsoil erosion from
excessive cultivation for weed control ( declines in
humic matter indicate erosion losses) and to avoid
accumulation of excess phosphorus and micronutrients
following application of manures and composts.
Composts and Manures
Specific guidelines must be followed when applying
composts and manures in organic farming systems.
Materials must be applied at agronomic rates in com-pliance
with any applicable nutrient management
guidelines and in ways that avoid excess nutrients ( see
http:// www. soil. ncsu. edu/ nmp/ ncnmwg/ or contact
your local Soil and Water Conservation District office).
Raw animal manures must be
• composted according to specific criteria,
• applied to land used for a crop not intended for
human consumption,
• incorporated into the soil at least 90 days prior to
the harvest of an edible ( human- consumed)
product not contacting soil or soil particles, or
• incorporated into the soil at least 120 days prior to
the harvest of an edible product that does con-tact
soil or soil particles.
The guidelines for compost production for organic
agriculture state that the initial C: N ratio must be be-tween
25: 1 and 40: 1, and a temperature between 131 º
and 170 º F must be achieved. This temperature must be
maintained for at least 3 days for in- vessel or static-aerated
pile systems or for at least 15 days during
which there are at least five turnings for windrow sys-tems.
Composts not meeting these criteria must be
applied based on other raw manure criteria, which also
apply to lagoon liquids, lagoon solids, and stockpiled
poultry litter. Ashes of manures may not be used, but
ashes from other untreated plant and animal materials
may be applied if not combined with any prohibited
substances.
Avoid over- reliance on animal manures, since this
could lead to accumulation of excess phosphorus, cop-per,
and zinc in soils. For example, based on the gen-eral
nutrient contents shown in Tables 6- 1 and 6- 2,
stockpiled turkey litter, applied at a rate of 5 tons per
acre, would supply approximately the amount of N
removed by a 150 bushel per acre corn crop. Note that
the amount of phosphorus added ( as P 2 O 5 equivalent)
would be 360 pounds per acre, while crop removal
would only be 53 pounds per acre. Similarly, 2.8
pounds per acre of zinc would be added, while crop
removal would only be 0.15 pounds per acre. Sporadic
use of manures in conjunction with more frequent use
of legume cover crops, green manures, or other N
sources is an excellent way to supply plant nutrients in
appropriate amounts.
NC State University Soilfacts bulletins describe
specific types of manures ( such as swine, poultry,
and dairy) at http:// www. soil. ncsu. edu/ about/ publi-cations/
index. php). Since nutrient composition of
animal manures and composts can vary widely, it is
wise to submit a sample to the Plant and Waste
Analysis Laboratory of the NCDA& CS Agronomic
Division before use. Sewage sludge and composted
municipal wastes are not allowed on organic fields.
North Carolina Organic Grain Production Guide 27
Chapter 7. Weed Management
Mike Burton, Assistant Professor, Crop Science, NC State University
Randy Weisz, Crop Science Extension Specialist, NC State University
Alan York, Crop Science Extension Specialist, NC State University
Molly Hamilton, Crop Science Extension Assistant, NC State University
Weed pest management must be an ongoing consid-eration
for organic farmers to achieve acceptable
yields and crop quality. A system of weed manage-ment
that includes multiple tactics will help reduce
losses in both the short and long term. Various weed
management tactics fall into two major categories:
cultural and mechanical. Cultural tactics are associ-ated
with enhancing crop growth or cover, while
mechanical tactics are used to kill, injure, or bury
weeds. During a cropping season, successful organic
weed management will rely on the cultural tactics
described below to achieve competitive crop plants
and will use the mechanical tactics to reduce the
weed population that emerges in the crop. When a
cash crop is not in the field, plant a cover crop or use
an occasional shallow tillage to kill germinating and
emerging weeds.
Cultural Tactics
Crop rotation
It is beneficial to have a rotation system that includes
crops with different life cycles, growth patterns, and
management techniques. This will reduce the chance
that weeds can proliferate over successive years. For
example, a rotation could include a summer crop,
winter crop, legume, grass, a cultivated crop ( corn)
and a noncultivated crop ( wheat or hay). Because
some weeds are triggered to germinate by tillage,
rotations of tilled and no- till crops ( such as a forage
or hay crop) may also be of benefit.
Cultivar and cover crop selection
Competitive differences exist among crop cultivars.
Tall cultivars and cultivars with rapid establishment
and quick canopy closure are reportedly more competi-tive
with weeds than short or dwarf cultivars or culti-vars
( or seedlots) that
have low seed vigor, are
slow growing, or are less
bushy. Some weed spe-cies
are suppressed by
crop- produced allelo-chemicals
( naturally produced compounds that can
inhibit the growth of other plants) in standing crops or
in residues of allelopathic crops ( for example, a rye
cover crop). Results of studies conducted with wheat
and rye have demonstrated that the production of
allelochemicals varies widely with cultivar and can
change in concentration during crop development.
Allelopathic characteristics of cultivars are being inves-tigated
in the small grains breeding programs at several
universities.
Seed quality
Seed cleanliness, percent germination, and vigor are
characteristics that can influence the competitive
ability of the seedlings. Seed that has not been care-fully
screened ( especially farmer- saved seed) is often
of lower quality than certified seed and may contain
unknown quantities of weed seed or disease. Plant-ing
this seed may result in the introduction of pests
not previously observed on the farm. There is also a
risk that weed density will increase and that weeds will
be introduced to previously uninfested parts of the
field. Germination rate and vigor are equally important
to weed management because they collectively affect
stand quality and time to canopy closure.
Planting – sowing date, seeding rate, row spacing,
and population.
Sowing date and seeding rate affect the final crop
population, which must be optimum to compete with
weeds. Carefully maintained and adjusted planting
Top. Row cultivator shovel.
Below. Flex- tine weeder.
28 North Carolina Organic Grain Production Guide
equipment will ensure that the crop seed is uniformly
planted at the correct depth for optimum emergence.
Narrower rows and a slightly increased plant popula-tion
( up to 10 percent higher than usual) will also
help the crop compete with weeds.
Cover crops
Cover crops can provide benefits of reduced soil ero-sion,
increased soil nitrogen, and weed suppression
through allelopathy, light interception, and the physical
barrier of plant residues. Cover crops such as rye, triti-cale,
soybean, cowpea, or clover can be tilled in as a
green manure, allowed to winter kill, or be killed or
suppressed by undercutting with cultivator sweeps,
mowing, or rolling. Warm- season cover crops help to
suppress weeds by establishing quickly and out- com-peting
weeds for resources. It is important to manage
cover crops carefully so that they do not set seed in the
field and become weed problems themselves.
Fertility— compost and manures
Uncomposted or poorly composted materials and
manures can be a major avenue for the introduction
of weed seeds. However, soil fertility that promotes
early and sustained crop growth helps to reduce the
chance that weeds will establish a foothold. Areas of
poor productivity leave the door open to diseases,
insect pests, and weeds.
Sanitation and field selection
Weeds are often spread from field to field on tillage,
cultivation, or mowing equipment. Cleaning equip-ment
before moving from one field to another or
even after going through a particularly weedy sec-tion
can prevent weeds from spreading between
fields or within fields. A short investment of time to
clean equipment can pay large dividends if it pre-vents
spread of problem weeds. When transitioning
to organic systems, it is highly advisable to start with
fields that are known to have low weed infestations.
Fields with problem weeds, such as Italian ryegrass,
wild garlic, Johnsongrass, or bermudagrass, should
be avoided if possible, as these weed species will be
difficult to manage.
Mechanical Tactics
A healthy, vigorous crop is one of the best means of
suppressing weeds. However, some physical tactics
are almost always needed to provide additional
weed control. The methods discribed below can be
used together with good cultural practices to kill or
suppress weeds – leaving the advantage to the crop.
The goals of mechanical weed control are to elimi-nate
the bulk of the weed population before it com-petes
with the crop and to reduce the weed seed
bank in the field. Important factors to consider for
mechanical weed control are weed species present
and their size, soil condition, available equipment,
crop species and size, and weather. Since it might
not be necessary to use a tactic on the entire field,
knowledge of weed distribution and severity can be
valuable. Tillage, blind cultivation ( shallow tillage
of the entire field after planting), and between- row
cultivation are important aspects of mechanical
weed control.
Tillage
Proper field tillage is important to creating a good
seedbed for uniform crop establishment, which is a
critical part of a crop’s ability to compete with
weeds. Tillage should also kill weeds that have al-ready
emerged. In the spring when the soil is warm,
weed seeds often germinate in a flush after tillage. A
moldboard plow will bury the weed seeds on or near
the surface ( those that come out of dormancy as the
soil warms) and bring up dormant weed seeds from
deeper in the soil. These weed seeds will normally
be slower to come out of dormancy than weed seeds
previously near the surface. Chisel plowing or
disking does not invert the soil and can result in an
early flush of weeds that will compete with the crop.
If there is enough time before planting, the stale
seedbed technique can be used as an alternate ap-proach.
In this technique, soil is tilled early ( a seed-bed
is prepared), which encourages weed flushes,
and then shallow tillage, flaming, or an organically
approved herbicide is used to kill the emerged or
North Carolina Organic Grain Production Guide 29
emerging weed seedlings. While this technique
should not be used in erosion- prone soils, it can be
used to eliminate the first flush or flushes of weeds
that would compete with the crop.
Blind cultivation
Blind cultivation is the shallow tillage of the entire
field after the crop has been seeded. Generally, it is
used without regard for the row positions. It pro-vides
the best opportunity to destroy weeds that
would otherwise be growing within the rows and
that are not likely to be removed by subsequent me-chanical
tactics. Blind cultivation stirs soil above the
level of seed placement ( further emphasizing the
need for accurate placement of the crop seed), caus-ing
the desiccation and death of tiny germinating
weed seedlings. Crop seeds germinating below the
level of cultivation should not be injured. The first
blind cultivation pass is usually performed immedi-ately
before the crop emerges, and a second pass is
performed about a week later. This depends, of
course, on weather, soil and crop conditions, and
weed pressure. Blind cultivation is most effective
when the soil is fairly dry and the weather is warm
and sunny to allow for effective weed desiccation.
Blind cultivation equipment includes rotary hoes,
tine weeders, spike tooth harrows, springtooth har-rows,
and chain link harrows.
Between- row cultivation
Between- row cultivation should not be the pri-mary
mechanical weed control tactic, but should
be used as a follow- up tactic to control weeds that
escaped previous efforts. Between- row cultivation
should be implemented when weeds are about 1-
inch tall and the crop is large enough not to be
covered by soil thrown up during the cultivation
pass. Usually, more than one cultivation pass is
needed. It may be useful to reverse the direction
of the second cultivation pass in order to increase
the possibility of removing weeds that were
missed by the first cultivation. Planting corn in
furrows can allow more soil to be moved on top
of weeds and may be a useful practice on some
farms. All cultivation passes should be done be-fore
the canopy closes or shades the area between
the rows. After this time, the need for cultivation
should decrease, as shading from the crop canopy
will reduce weed seed germination and equipment
operations can severely damage crop plants. Cul-tivation
works best when the ground is fairly dry
and the soil is in good physical condition.
There are many types of cultivator teeth, shanks, and
points. Choose the cultivating equipment that works
best in your soils. Points for cultivator teeth vary in
type and width. Half sweeps ( next to the row) and
full sweeps ( between rows) are probably the most
versatile and common, but each type of point works
best under certain conditions and on certain weed
species. Using fenders on cultivators at the first pass
can keep the soil from covering up the crop. Cultiva-tor
adjustments are very important and should be
made to fit the field conditions. Tractor speed should
also be modified through the field to compensate for
variability in soil type and moisture.
Other methods of mechanical weed control may
be effective and efficient depending on the available
equipment, budget, and goals of the farm.
Flame weeding
Flame weeding provides fairly effective weed con-trol
on many newly emerged broadleaf species and
can be used in tilled or no- till fields. Grasses may
not be well controlled by flaming because their
growing points are often below the soil surface.
Flame weeding should only be performed when field
moisture levels are high and when the crop is small.
Hand weeding and topping
Walking fields and hand weeding or topping ( cutting
off the weed tops) can vastly increase familiarity with
the condition of the crop and distribution of weeds or
other pests. Farmers who are familiar with problem
locations can remove patches of prolific weeds before
they produce viable seeds and reduce long- term prob-lems
caused by weeds that escaped management. Top-ping
of flowering weeds can reduce seed set and the
weed seed bank in the field.
30 North Carolina Organic Grain Production Guide
Herbicides
Several herbicides have been approved for certified
organic farming. These include acetic acid ( distilled
vinegar), clove oil, nondetergent soap- based pesticides,
some corn gluten meal products, and boiling water.
While these products have potential for controlling
weeds in organic farming systems, no research has
been conducted with them in grain crops in North
Carolina. Therefore, we cannot give recommendations
for their use in this state. The cost of herbicides ap-proved
for organic farming may also be prohibitively
expensive for field crops. The Organic Materials Re-view
Institute ( OMRI) publishes a list of commercially
available products that can be used in certified organic
operations for weed control ( www. OMRI. org). Condi-tions
for use of an approved herbicide must be docu-mented
in the organic system plan as specified in the
2000 National Organic Plan.
No- till Organic Weed Control
Recent research on no- till organic agriculture shows
some potential for organic systems to be much less
reliant upon mechanical weed control. The basic
premise for no- till organic weed control is to plant a
cover crop with high residue, mow or roll that cover
crop, and no- till plant into the residue. This system,
however, takes a lot of planning to work well. For
more information on organic no- till farming, contact
the Rodale Institute by mail at 611 Siegfriedale
Road, Kutztown, PA 19530- 9320, by telephone at
610- 683- 1400, or on the Web: http://
www. rodaleinstitute. org.
Weed Guides
Several weed identification guides are available for purchase through various publishers. NC State
University offers Identifying Seedling and Mature Weeds, an excellent and inexpensive resource
developed for the southeastern United States. It does not, however, include some weed species that are
troublesome in North Carolina grain crop production. Another recommended guide is Weeds of the
Northeast. A few guides are also available on the Web:
http:// www. ppws. vt. edu/ weedindex. htm
http:// web. aces. uiuc. edu/ weedid/
http:// www. weeds. iastate. edu/ weednews/ ncseed. htm
Ordering information
Identifying Seedling and Mature Weeds ( AG- 208). Stuckey, Monaco and Worsham. ( 1989).
Communication Services, Box 7603, NC State University, Raleigh, NC 27695- 7603. Telephone: 919-
513- 3045. $ 10.
Weeds of the Northeast. Uva, Neal and DiTomaso ( 1997). Cornell University Press,
P. O. Box 6525, Ithaca, NY 14851- 6525. Telephone: 607- 277- 2211
North Carolina Organic Grain Production Guide 31
Chapter 8. Organic Certification
Jim Riddle, Organic Policy Specialist, Rodale Institute’s The New Farm ®
Myron Fountain, former Executive Director, North Carolina Crop Improvement Association
Tony Kleese, Executive Director, Carolina Farm Stewardship Association
In order to sell, label, or represent their products
as “ organic,” growers who sell $ 5,000 ( or more) a
year of organic products must be certified by a
USDA- accredited certifying agent. The National
Organic Program Final Rule ( NOPFR) spells out
requirements for organic crop and livestock pro-duction,
handling, certification, and record- keep-ing.
The NOPFR, and other related documents,
can be viewed on the Web at www. ams. usda. gov/
nop/. ( See Table 8.1.)
Who Must Be Certified?
If an operation earns $ 5,000 ( or more) in a year
from organic agricultural products, that operation
must be certified. Operations selling less than
$ 5,000 a year in organic agricultural products and
direct marketing the products to the end- user are
exempt from certification, but they must operate in
compliance with the federal regulations and may not
label products as certified organic.
Organic Certification Process
Because all certifiers must follow USDA require-ments,
the organic certification process is similar
across certifiers. First, farms must comply with the
federal standards for organic production ( Table 8- 1).
The next steps involve choosing a certifier and com-pleting
an Organic Farm ( or System) Plan. The Or-ganic
Farm Plan is also considered the application
for certification. The certifying agent may ask ques-tions
to assess the applicant’s eligibility. The Or-ganic
Farm Plan Questionnaire must be completed,
including farm maps and a three- year field history
for crops planted and inputs applied. The completed
Organic Farm Plan ( the application), licensing agree-ment,
and fees should then be submitted to the certi-fication
agency.
The certifying agent then reviews the Organic
Farm Plan and accompanying documentation to en-sure
completeness and determine whether the appli-cant
appears to comply or has the ability to comply.
The certifying agent also verifies information regard-ing
any previous certifications, notification of non-compliance,
or denials of certification.
The next step of the process is an on- site inspec-tion
of the farm. The certifying agent assigns an
organic inspector who calls the applicant to set up an
appointment. The inspection may take 3 to 6 hours,
depending on the complexity of the operation. In-spectors
need to verify information from the Organic
Farm Plan. They inspect fields, farm buildings and
equipment, assess contamination risks, fill out an on-site
inspection report, and gather as much informa-tion
as needed to determine if the operation is in
compliance. Inspectors evaluate crop health and
growth, soil tilth, the fertility management program,
pest and weed management strategies, and the
applicant’s understanding and commitment to compli-ance.
They also review records to ensure monitoring
and compliance. The inspector may be authorized to
take soil, tissue, or product samples for analysis. The
inspector reviews identified noncompliance issues at
the time of the inspection. The inspector conducts an
exit interview to confirm the accuracy and complete-ness
of the observations and information gathered,
addresses the need for additional information, and dis-cusses
issues of concern. The inspector also completes
a report based on the information gathered. The inspec-tor
does not make the certification decision, but identi-fies
noncompliance issues with regard to organic
standards. The inspection report and all associated
paperwork are sent to the certifying agent.
32 North Carolina Organic Grain Production Guide
Table 8- 1. Organic certification federal standards
To become a certified organic production operation, the farm and farm practices must comply with the Organic
Foods Production Act of 1990 and the USDA National Organic Program rules and regulations ( Federal Register, Vol.
65, No. 246, pgs. 80367- 80663).
In simplified terms, National Organic Standards for crop farms require
• three years ( 36 months prior to harvest) with no application of prohibited materials ( no synthetic fertilizers, pesti-cides,
or GMOs) prior to certification;
• distinct, defined boundaries for the operation;
• implementation of an Organic System Plan, with proactive fertility systems; conservation measures; and environ-mentally
sound manure, weed, disease, and pest management practices;
• monitoring of the operation’s management practices;
• use of natural inputs and/ or approved synthetic substances on the National List, provided that proactive manage-ment
practices are implemented prior to use of approved inputs;
• use of organic seeds, when commercially available ( no use of seeds treated with prohibited synthetic materials
such as fungicides); and
• use of organic seedlings for annual crops ( see text discussion).
National Organic Standards prohibit
• use of genetically engineered organisms, ( GMOs) defined in the rule as “ excluded methods”;
• residues of prohibited substances exceeding 5 percent of the EPA tolerance ( certifier may require residue analysis
if there is reason to believe that a crop has come in contact with prohibited substances or was produced using
GMOs);
• sewage sludge or irradiation;
• raw manure and compost ( see text discussion);
• any other prohibited substances on the National List; and
• field burning to dispose of crop residues ( may only burn to suppress disease or stimulate seed germination – flame
weeding is allowed).
In addition, organic operations must
• maintain or improve the physical, chemical, and biological condition of the soil, minimize soil erosion, and imple-ment
soil- building crop rotations;
• use fertility management systems that do not contaminate crops, soil, or water with plant nutrients, pathogens,
heavy metals, or prohibited substances;
• maintain buffer zones, depending on risk of contamination;
• prevent commingling on split operations ( the entire farm does not have to be converted to organic production,
provided that sufficient measures are in place to segregate organic from nonorganic crops and production in-puts);
and
• maintain records.
North Carolina Organic Grain Production Guide 33
A certification committee, staff member, or re-view
committee reviews the Organic Farm Plan, the
inspection report, and all associated documentation.
If the certifying agent determines compliance in all
procedures and activities, the applicant is granted
certification and is issued a certificate of organic
operation. If the certifying agent determines any
minor noncompliances, the applicant has the oppor-tunity
to correct these noncompliances as a condition
of certification.
To continue organic certification each year, the
certified farmer must pay annual certification fees,
submit an updated Organic Farm Plan detailing
changes from the previous year, and submit an up-date
on correction of minor noncompliances previ-ously
identified by the certifying agent. Other
records or information may be needed if deemed
necessary. Each farm must be inspected at least once
annually to maintain certification. The updated Or-ganic
Farm Plan and inspection report must also be
completely reviewed by the certifying agent to re-ceive
an updated certificate for the organic opera-tion.
Denial of Certification
If certification is to be denied, the certifying
agent must provide an applicant with written notifi-cation
of noncompliance, giving the date by which
the correction must be accomplished, and specifying
any documentation necessary to support correction.
The applicant may rebut in writing any noncom-pliances
identified by the certifying agent. When a
correction is not possible, a notification of noncom-pliance
and notification of denial of certification is
provided to the applicant. This notification is also
provided to the USDA National Organic Program
Administrator. The applicant may re- apply for certi-fication
or request mediation with the certifying
agent. The applicant may file an appeal of the denial
of certification to the USDA National Organic Pro-gram
Administrator. If the certifying agent has rea-son
to believe that the applicant has made false state-ments
or otherwise misrepresented compliance, the
certifying agent may also deny certification simulta-neously
with issuance of notification of noncompli-ance.
Record- keeping Requirements for
Certified Operations
Record- keeping is very important to organic certifi-cation.
A certified operation must maintain records
concerning the production, harvest, and handling of
agricultural products that are intended to be sold,
labeled, or represented as organic. The records must
be adapted to the particular business that the certified
operation is conducting. For example, an organic
grain production farm must keep records pertaining
to the particular operations that deal with the produc-tion,
handling, and marketing of the organic grain
crops, such as storage, clean- out, and transportation
records. The records must also fully disclose all ac-tivities
and transactions of the certified operation in
sufficient detail as to be readily understood and au-dited.
Records must be maintained for at least five
years beyond their creation and be sufficient to dem-onstrate
compliance with the National Organic Plan
rules and regulations. The certified operation must
make all relevant records available for inspection
and copying during normal business hours by autho-rized
representatives of the Secretary of Agriculture,
the applicable state program’s governing official,
and the certifying agent.
Certification Agencies
A list of all USDA- accredited organic certifying
agencies can be found on the Web at
www. ams. usda. gov/ nop/ CertifyingAgents/
Accredited. html or by request through the National
Organic Plan ( NOP) office at 1400 Independence
Avenue, SW, Room 2510 South Building, Washing-ton,
DC, 20250.
34 North Carolina Organic Grain Production Guide
Choosing a Certifier
When choosing an organic certifier, an applicant
should consider several factors. First, it may be
helpful to choose a certifier that the end- user of
your product recommends or recognizes. The lo-cation
of inspectors that the certifier uses should
also be considered, as most certifiers require the
applicant to pay all expenses associated with the
on- site inspection, including travel. Since the
USDA requires that certifiers fully disclose all
fees, an applicant can compare certifiers based on
expense or fees. Also consider the turn- around
time required by certifiers to obtain certification,
and the experience the certifier has in certifying a
particular type of operation. Some applicants
choose their certifier based on the agency’s level
of involvement in organic certification policy and
advocacy at state and national levels.
Specific Requirements
and Suggestions for Organic
Compliance in Grain Production
Isolation buffers
The size of isolation buffers between organic land
and adjacent nonorganic land depends on land uses,
prevailing winds, runoff directions, ditches, and
other barriers. It is usually between 20 and 50 feet.
However, cross- pollinated or wind- pollinated or-ganic
crops ( such as corn), should be isolated from
nonorganic crops of the same type by 660 feet to
maintain seed purity. If an applicant can verify with
a written statement from his or her neighbors that no
prohibited materials are being used on adjoining
land, then the applicant may not need a buffer at all.
Organic seed
Organic seed must be used when commercially
available. However, in many cases, the crop or vari-ety
desired is not commercially available as organic
seed. Generally, the applicant must contact at least
three seed companies or sources that carry organic
seeds in an effort to obtain organic seed of the crop
or variety desired. The three seed sources contacted
must produce or supply seed of the crop kind de-sired.
The applicant must also document the contact
( including the date; whether the contact involved a
telephone, fax, letter, or email message; the crop and
variety; and the most comparable variety with or-ganic
seed source and price). A copy of this docu-mentation
may be required by the organic certifier if
seed is used that is not organic. Excellent resources
for availability of organic seed for crop production
can be found by contacting these organizations:
• http:// attra. ncat. org/ attra- pub/ altseed. html
National Sustainable Agriculture Information
Service, 1- 800- 346- 9140
P. O. Box 3657, Fayetteville, AR 72702
• http:// www. savingourseed. org/
Save Our Seed, 540- 894- 8866
286 Dixie Hollow, Louisa, VA 23093
• http:// www. omri. org/ OMRI_ SEED_ list. html
Organic Materials Review Institute, 541- 343-
7600. Box 11558, Eugene, OR 97440
Split ( nonorganic and organic) production
A split operation may require additional record- keep-ing
and detailed auditing. The dates of use, cleaning,
and purging of equipment ( including field prepara-tion,
cultivation, harvesting, and handling equip-ment)
used in both nonorganic and organic opera-tions
must be recorded.
Accidental contamination
Accidental contamination of a farm by prohibited
substances can be a result of spraying by the Depart-ment
of Transportation ( DOT), electrical companies,
or neighbors. It is important to communicate very
clearly about your organic operation and display
signs that indicate organic land. The DOT and elec-trical
companies should be informed of the location
of organic land and be specifically asked to avoid
spraying the area.
North Carolina Organic Grain Production Guide 35
Storage and product transportation
Organic and nonorganic grain ( or field crops) must
not commingle. Storage bins or containers and areas
used for organic grains should be thoroughly cleaned
before use and clearly labeled “ organic.” Documen-tation
of the cleaning of transportation vehicles will
be required. The date, previous product transported,
organic product transported, cleaning activity, and
name( s) of the driver( s) are generally needed for the
documentation. Consult the certifier about specific
cleanout procedures.
Pesticides
A number of pesticides— mainly nonsynthetic compounds and biocontrols— are approved for
use in certified organic production systems. Insecticides include neem, Bacillus thuringiensis,
Beauvaria spp., diatomaceous earth, pyrethrum, spinosads, horticultural oils, and species of Tricho-derma.
Fungicides include hydrogen peroxide, potassium and sodium bicarbonate, copper products,
sulfur, species of Pseudomonas, and pesticidal soaps. While these products have potential for con-trolling
insect or disease pests, or both, no research has been conducted with them in grain crops in
North Carolina, and we cannot make recommendations for their use in this state. The cost of pesti-cides
approved for organic production may also be prohibitively expensive for field crops. Condi-tions
for use of an approved pesticide must be documented in the organic system plan as required by
the 2000 National Organic Plan.
The Organic Materials Review Institute ( OMRI) publishes a list of commercially available
products that can be used in certified organic operations for pest control: www. OMRI. org.
36 North Carolina Organic Grain Production Guide
However, there are markets in North Carolina for
food- grade organic wheat.
Marketing Plan
It is always a good idea to have a marketing plan,
especially when marketing organic grains. Research
for a market is a key component of success in mar-keting
organic grains. Begin researching the market
before the crop is planted. Talk to organic grain buy-ers,
organic certifiers, suppliers, and other organic
grain farmers to gather information on how best to
market your crop. The Internet can be a good re-source
for current information. As a first step, see
“ Marketing Resources” on this Web site:
www. cropsci. ncsu. edu/ organicgrains/ marketing.
marketing. htm.
It is important to know your customers and
know what they want, whether they are brokers,
processors, retailers or end- users. Find out if buyers
are looking for a certain variety of grain or a certain
quantity and whether they have quality specifica-tions
for the grain. Most buyers want to buy organic
grain on a clean, delivered basis. If other arrange-ments
are desired, the farmer may need to negotiate
with the buyer. It is also important to know what
price buyers are willing to pay for grain, and when
and how they will pay. Transportation is another
critical consideration in a marketing plan. How will
the product get to the consumer and when? What are
the costs? Good record- keeping is also a key part of
a marketing plan and will keep a farmer knowledge-able
about how profitable the operation is and where
improvements can be made.
Storage
Storage may be critical for marketing organic grains.
Buyers sometimes do not have sufficient storage
Chapter 9. Marketing Organic Grain and Oilseed Crops
Molly Hamilton, Crop Science Extension Assistant, NC State University
Marketing organic grains is very different from mar-keting
conventional grains. Organic grain is usually
sold to a specific buyer, while a farmer using con-ventional
methods can deposit an entire harvest at
the local grain elevator. For North Carolina farmers,
the organic grain buyers are almost always farther
away from farms than conventional markets, which
means freight costs are an additional consideration.
The National Organic Final Rule ( NOFR) requires
that organic grain be handled, processed, and stored
in facilities separate from conventionally grown and
handled grain. This means that in a split operation
( with both conventional and organic grain produc-tion),
harvesting, transportation, and storage equip-ment
for organic grain needs to be separate in time
or space from equipment used in handling conven-tional
grain. However, organically produced crops
can bring higher prices than conventional crops, so
the extra trouble in getting the crop to market may be
financially beneficial.
The Marketplace
Nearly all organic grains are marketed as either live-stock
feed or as food for human consumption. Or-ganic
grain for human consumption, referred to here
as “ food- grade grain,” generally earns a higher pre-mium
than organic grain for livestock feed. How-ever,
growing for the livestock feed market lowers
the risk of going organic for those who are new to
organic farming. Growing organic grain for the food-grade
market requires a lot of attention to detail and
experience with organic grain production and mar-keting.
Quality specifications are more stringent than
for livestock- feed grain, and markets are usually
harder to identify. Often a specific variety is required
by a buyer of a food- grade grain. For most North
Carolina farmers, the livestock feed market is more
easily accessible than the food- grade grain market.
North Carolina Organic Grain Production Guide 37
capacity, cash- flow, or both to accept an entire
crop at one time. A crop may need to be stored for
several weeks or months. Often, a better price for
the grain is offered a few months after harvest, so
storage may also be an economic advantage. To
maintain grain quality during storage, insects
must be kept out, and the grain must be stored at
proper temperature and moisture conditions. Split
operations will need separate storage bins, or stor-age
bins will need to be thoroughly cleaned
( swept, vacuumed, blown out with pressurized air,
or all of these) to prevent commingling of organic
and conventional products. Storage bins should be
labeled, and records of their contents should be
maintained.
The best way to manage insect pests in stored
organic grains is to avoid them. It is important to
prevent problems in stored grain by keeping bins,
ducts, and augers clean and by storing grain at a
temperature lower than 60° F and at low humidity.
Another suggested and often used method to pre-vent
insect pest problems in stored organic wheat
and corn is to add food- grade diatomaceous earth
( DE) to the grain as it is being loaded into the
storage bins ( at a rate of up to 40 pounds per
1,000 pounds of grain). Diatomaceous earth can
be sprinkled on top of the corn while it is moving
in the auger to the bin, and then on top of the corn
after it is loaded. DE works because the surface of
each particle is very sharp on a microscopic level,
and these sharp edges cut into worms as they feed
or move over the grain, causing them to desiccate.
Be sure to talk to your grain buyer and certifier
before using DE as a storage additive. To identify
insect pests of stored grain, see the North Caro-lina
Small Grain Production Guide or the North
Carolina Corn Production Guide storage sections.
These publications are available through county
Extension centers or on the Web:
http:// www. smallgrains. ncsu. edu/ Guide/ cover. html
http:// www. ces. ncsu. edu/ plymouth/ cropsci/ cornguide/
Genetic Contamination
Organic integrity must be maintained throughout the
growing, harvesting, storage, and transportation
processes. Because organic standards prohibit the
use of genetically modified organisms, proper har-vesting
and storage procedures are an essential part
of organic grain marketing. A positive test result ( a
GMO percentage above a certain level) can cause a
buyer to reject an entire load. If the farm is a split
operation, thorough cleaning of harvest equipment
( including hauling equipment and all augers) be-tween
operations for conventional and organic crops
is very important. Grain- receiving pits, augers or
conveyors, elevator legs, dryers, and storage bins are
all sources of contamination and should be cleaned
to minimize mixing. Running some organic grain at
maximum capacity through the system to clean out
any residual transgenic grain can also help reduce
contamination risks. It may be prudent to harvest the
outside rows of organic grain fields ( especially of
wind- pollinated grains) first and store and sell this
grain as conventional. Doing this eliminates much of
the contamination risk associated with cross- pollina-tion
from transgenic crops.
Transportation
Organic grain buyers generally need the grain deliv-ered
to their facilities and they pay on a delivered
basis. This means that the grower is often respon-sible
for transportation. Trucks that transport grain
from the farm to buyers should be cleaned thor-oughly
before loading organic grain. It is important
to remember to clean the hopper bottoms and any
covering ( such as canvas) on the truck as well as the
bed. Document the cleaning, as this may be needed
by the buyer and the certifier. Documentation can be
a written statement or affidavit that says when and
how the cleaning was done. It shows that the pro-ducer
is taking responsibility for the cleanliness of
the transportation vehicle.
38 North Carolina Organic Grain Production Guide
Grain Quality
Grain quality is very important to food- grade grain
as well as livestock- feed grain. The quality of the
grain determines its value. High- quality grain must
be clean and free of weed seed, undamaged, uncon-taminated,
and identifiable. Controlling weeds, pests,
and volunteer crops in

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North Carolina Organic Grain Production Guide 1
North Carolina Organic Grain
Production Guide
North Carolina State University
North Carolina Organic Grain Project
College of Agriculture and Life Sciences
Prepared by:
Molly Hamilton, Crop Science Extension Assistant, NC State University
With contributions from:
Keith Baldwin, Extension Specialist, North Carolina A& T State University
Gary Bullen, Extension Associate, Agriculture and Resource Economics, NC State
University
Mike Burton, Assistant Professor, Crop Science, NC State University
Carl Crozier, Soil Science Extension Specialist, NC State University
Jim Dunphy, Crop Science Extension Specialist, NC State University
John Van Duyn, Entomology Extension Specialist, NC State University
Myron Fountain, former Executive Director, North Carolina Crop Improvement Association
Ron Heiniger, Crop Science Extension Specialist, NC State University
David Howle, Assistant Professor, Fertilizer and Seed Certification, Clemson University
Tony Kleese, Executive Director, Carolina Farm Stewardship Association
Jim Riddle, Organic Policy Specialist, Rodale Institute’s www. newfarm. org
Phil Rzewnicki, Teaching Assistant Professor, NC State University
Randy Weisz, Crop Science Extension Specialist, NC State University
Alan York, Crop Science Extension Specialist, NC State University
Acknowledgments
This publication is supported in part by a grant from the Z. Smith Reynolds Foundation.
2 North Carolina Organic Grain Production Guide
Contents
Page
Chapter 1. Introduction ........................................................................................................................... 3
Chapter 2. Organic Crop Production Systems ........................................................................................ 4
Chapter 3. Crop Production Management – Corn .................................................................................. 6
Chapter 4. Crop Production Management – Wheat and Small Grains ................................................. 12
Chapter 5. Crop Production Management – Soybean .......................................................................... 18
Chapter 6. Soil Management ................................................................................................................ 22
Chapter 7. Weed Management ............................................................................................................. 27
Chapter 8. Organic Certification ............................................................................................................ 31
Chapter 9. Marketing Organic Grain and Oilseed Crops ...................................................................... 36
Chapter 10. Crop Budgets ...................................................................................................................... 40
Resources ............................................................................................................................... ............ 46
Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the
reader. The use of brand names and any mention or listing of commercial products or services in this publication
does not imply endorsement by North Carolina Cooperative Extension nor discrimination against similar
products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that
the intended use complies with current regulations and the product label. Be sure to obtain current information
about usage regulations and examine a current product label before applying any chemical. For assistance,
contact your county Cooperative Extension agent.
North Carolina Organic Grain Production Guide 3
Chapter 1. Introduction
Phil Rzewnicki, Teaching Assistant Professor, NC State University
Molly Hamilton, Crop Science Extension Assistant, NC State University
The market for organic products is growing at a
rapid pace. In the United States, the organic food
industry grew between 17 and 21 percent each year
from 1997 to 2003, and an average annual growth
rate of 18 percent has been forecast through 2008
according to the Organic Trade Association
( www. ota. com). In 2003, the market growth of or-ganic
bread and grains was over 20 percent, with
growth of organic meat, poultry, and fish near 78
percent. These trends are expected to continue.
To be certified as organic, livestock must be
fed organic grains as required by the U. S. Depart-ment
of Agriculture ( USDA) National Organic
Plan Rules. This requirement leads to more oppor-tunities
for production of organic grains. In North
Carolina, organic grain producers have expanding
opportunities to market their products to manufac-turers
that create foods for human consumption as
well as to livestock feed markets. Organic grain
prices are usually 150 percent higher than prices
for conventionally- produced grain. Other benefits
of organic grain production include increased soil
health, farm income diversification, and lower
levels of exposure to common farm chemicals for
both people and the environment. Farmers in
North Carolina are in a unique position to take
advantage of the early growth of organics by
growing and selling organically produced grain. If
they are to take advantage of the price premium
for organic products, however, more research on
organic grain and oilseed production in North
Carolina is needed. In addition, a network of or-ganic
grain farmers should be developed, and
marketing information and Extension education
should be made available to help growers compete
successfully in this rapidly expanding industry.
This guide provides farmers, Extension person-nel,
and other agricultural educators with informa-tion
about organic production, certification, and mar-keting
of grain crops as well as references to further
information ( see the “ Resources” section, pages 46-
48). It does not cover all aspects of grain production,
but focuses on specific techniques relevant to or-ganic
systems. Comprehensive guides to grain pro-duction
can be found in the latest editions of these
Extension publications:
• Small Grain Production Guide:
www. smallgrains. ncsu. edu/ Guide/ cover. html
• Corn Production Guide: http://
www. ces. ncsu. edu/ plymouth/ cropsci/
cornguide/
Additional information is available from the NC
State University Department of Crop Science:
www. cropsci. ncsu. edu.
This guide does not make recommendations
about the use of pesticides in organic systems. No
research has been published on the use of pesticides
approved for organic production of grain crops in
North Carolina, and we cannot make recommenda-tions
for their use here. The cost of pesticides ap-proved
for organic production may also be prohibi-tively
expensive for field crops. The Organic Materi-als
Review Institute ( OMRI) publishes a list of com-mercially
available products that can be used in cer-tified
organic operations for pest control
( www. OMRI. org). Conditions for use of an ap-proved
pesticide must be documented in the organic
system plan, as described by the 2000 National Or-ganic
Plan ( NOP).
We have made every effort to accurately cite
National Organic Plan regulations, production infor-mation,
and marketing information. Always consult
your certification agency when you have questions
about certification requirements specific to your
particular farm.
4 North Carolina Organic Grain Production Guide
Chapter 2. Organic Crop Production Systems
Ron Heiniger, Crop Science Extension Specialist, NC State University
Molly Hamilton, Crop Science Extension Assistant, NC State University
Organic production systems are based on manage-ment
practices that promote and enhance farm
biodiversity, biological cycles, and soil biological
activity. Organic agriculture strives to minimize use
of off- farm inputs and relies on management prac-tices
that restore, maintain, and enhance soil ecology
and the farm landscape. Growers considering organic
grain crops need to recognize that success will de-pend
on developing a diversified crop management
system, including an appropriate rotation plan. Rec-ommendations
in this guide were developed to help
growers tailor soil health and pest management strat-egies
to fit their specific conditions.
Components of Organic
Production Systems
Table 2- 1 lists the key components of an organic
production system. The choices made for each com-ponent
will affect the choices for other components
as well as soil fertility and pest management.
Table 2- 1. Components of cropping systems
Components Category
Crop sequence Rotations
Cover crops
Crop management Variety/ hybrid selection
Planting depth
Planting date
Plant population
Row width
Harvest and storage
Soil management Tillage practices
Fertility
Pest management Weed management
Insect management
Disease management
Crop Sequence
An organic production system begins with selection
of the best rotation sequence of production crops and
cover crops based on the specific characteristics of
the field. This is particularly important in the first
few years of an organic production system because
the transition period will set the conditions for suc-cess.
Rotation sequences should be designed to:
• reduce weed pressure by minimizing the
amount of weed seed produced and reducing
perennial weeds;
• increase the amount of mineralizable nitrogen
in the soil;
• reduce the incidence of insect and disease pests
by eliminating hosts and interrupting pest life
cycles.
This usually requires combinations or rotations
of crops that attract or harbor different insects and
diseases, fix nitrogen, inhibit weed growth, and en-hance
the soil. The following crop sequences are
recommended for organic grain crop production in
North Carolina.
Wheat – Red clover ( or other forage legume)
– Corn. Wheat and the legume provide continuous
ground cover, help break up pest cycles, reduce
warm- season weeds through the mowing of clover,
and increase available nitrogen. Tilling the clover
into the soil makes nitrogen available for the suc-ceeding
corn crop. Growing the legume for two sea-sons
will result in more nitrogen returned to the soil
and a longer period between corn crops to break pest
insect and disease cycles. However, in systems with-out
livestock, the legume cover crop might have
little economic value unless it can be cut and sold for
hay as an organic forage crop. Cutting for hay will
reduce the amount of biomass from residue and may
reduce the amount of nitrogen available to subse-quent
crops.
North Carolina Organic Grain Production Guide 5
Wheat – Soybean – Corn. This rotation has many
of the same advantages as the above rotation, but the
soybean crop can be harvested and marketed. One
disadvantage of this rotation is longer soil exposure
since soybean is planted after wheat and harvested
before corn. Weeds emerging in the soybean crop may
be difficult to control, and less nitrogen will be fixed by
the soybean crop. However, a cover crop could be
incorporated into this rotation to provide ground cover
when needed, to expand the rotation beyond two years,
or both. A short, two- year rotation will need to be ap-proved
by a certification agency.
Farmers who have long- established organic
fields usually use a longer rotation of four or five
years. A longer crop rotation could rely on one of
these sequences:
• Corn – rye cover crop – soybeans – rye or crim-son
clover cover crop – wheat – cowpea cover
crop.
• Corn – wheat – ( double cropped) soybeans –
crimson clover cover crop – sunflowers or sum-mer
cover crop – small grain ( oats, barley, triti-cale).
Legumes or other broadleaf crops should be grown
at least two of every five years. A well- developed crop-ping
sequence should result in minimal problems with
insects and plant diseases. Weeds are usually the major
issue for long- term organic systems, but even weed
problems can be managed through suppression by
particular cover crops and timely cultivation.
Transitioning to Organic Cropping Systems
A switch to organic production from conventional agriculture requires a 36- month transition
period. Experienced grain farmers can use their skills, knowledge, and experience with conventional
grains as a base to build new proficiency with crop rotation, cover crops, mechanical weed control,
record- keeping for certification, and marketing of organic crops. Most North Carolina farmers already
have rotations that include corn, wheat, and soybeans. Such farms can go organic with little capital
investment; however, mechanical weed equipment, separate storage facilities, or both may be needed for
organic harvests.
It is advisable to begin transitioning to organic with a relatively small acreage and carefully
chosen fields. Fields with low weed, insect, and disease pressures and with relatively good soils give the
best chance of success when starting with organic production. Fields with more intense pest problems or
soil requirements may take more experience with organic production to be successful.
Although crops produced during the transition to organic might be marketed for a premium over
conventional crops, return will be less than for certified organic crops. Some grain buyers in the Midwest
are looking for nontransgenic ( non- GMO) corn and soybeans, which must be used in transitional produc-tion.
Some livestock producers in North and South Carolina are also looking for nontransgenic grains for
feed and are willing to pay a small premium. These markets may be harder to identify than traditional
organic markets, but they can provide economic incentives during the transition years required to change
from conventional to organic farming. Some of these buyers register with this N. C. State University Web
site: www. cropsci. ncsu. edu/ organicgrains/ marketing/ buyers. htm.
6 North Carolina Organic Grain Production Guide
Chapter 3: Crop Production
Management— Corn
Ron Heiniger, Crop Science Extension Specialist, NC State University
John Van Duyn, Entomology Extension Specialist, NC State University
Production Management
Key management practices for organic corn produc-tion:
• Choose organically grown ( when possible),
non- GMO hybrids with high vigor, high
standability rates, disease and pest resistances,
stress tolerance, high yield, and a maturity
date of 112 days or less.
• Plant on time, at the proper depth, in a well-prepared
seedbed, on narrow rows.
• Rotate crops.
• Achieve proper soil pH and good fertility.
• Choose the correct plant population.
Hybrid Selection
For organic growers seeking to identify appropriate
corn hybrids, yield is not the primary consideration.
The key hybrid characteristics for organic corn pro-duction
are
• rapid early growth and vigor
• standability
• pest and disease resistance
• stress tolerance
• yield
Table 3- 1 provides a list of organic and conven-tional
untreated hybrids that have been evaluated and
rated for these key characteristics.
Rapid early growth and vigor
Rapid early growth is essential in minimizing the
effects of seedling diseases and insects, increasing
root volume, and competing with weeds. In general,
early growth is closely related to maturity date.
Early- to medium- maturing hybrids ( 102 to 114
days) tend to exhibit better early growth than do late
hybrids ( longer than 115 days). The best way to se-lect
hybrids with rapid early growth for North Caro-lina
is to contact Extension agents, seed company
representatives, and other organic growers who have
had experience with different corn hybrids.
Standability
Standability is an important measure of how well the
crop will stand under difficult environmental condi-tions.
Because pests affect stalk strength, an organic
hybrid needs to be able to resist lodging under stress.
Pest and disease resistance
Resistance to common seedling, leaf, and stalk dis-eases
is an important characteristic for hybrids in
organic production systems. Some hybrids even
tolerate insect pests such as European corn borer and
southern cornstalk borer. Growers should select hy-brids
that combine good early growth characteristics
with good resistance to diseases that are likely to be
problems in their fields.
Stress tolerance
Stress tolerance is the ability to produce acceptable
yield under drought or other environmental stresses.
Hybrid seed suppliers often refer to this characteris-tic
as “ drought tolerance.” This characteristic is im-portant
since limited available nitrogen, which is
often a problem in the early years of an organic sys-tem,
can lead to nutrient and drought stress. Hybrids
that can tolerate this stress will produce higher yields
and compete more successfully with weeds.
Yield
The only reliable indicators of yield potential in
organic systems will come from tests conducted
using organic practices. Most of the hybrid compari-
North Carolina Organic Grain Production Guide 7
sons done in organic systems use hybrids best suited
to the upper Midwest, and there is only a limited
amount of organic- yield test information available
in North Carolina. In these circumstances, grow-ers
may get the best information from local hybrid
comparisons when drought or other types of stress
were factors. For instance, official variety tests con-ducted
in North Carolina during 2002 reflect results
from drought conditions and might be indicators of
hybrid performance in organic systems. Those
hybrids with good compensating mechanisms may
do well in situations of low nitrogen availability
or high pest pressures. Growers should conduct
their own hybrid comparisons by selecting four to
six promising hybrids and evaluating them under
their own management practices. The best proce-dure
is the strip test, where each test hybrid is grown
adjacent to a standard hybrid ( see Figure 3- 1). This
pattern permits the yield data to be adjusted for
soil variability. If a standard is not used, test hy-brids
can be alternated with the hybrid that has
the best past performance. Growers conducting
their own hybrid evaluations should remember to
select uniform test fields to minimize soil vari-ability
and to restrict comparisons to hybrids of the
same maturity class.
Table 3- 1. Evaluations of organic and untreated corn hybrids for relative maturity, seed vigor, early growth rating,
standability, disease ratings, and stress tolerance.*
Relative Seed Early Standability Southern Corn Gray Stress
Hybrid Maturity Vigor Growth Rating Leaf Blight Leaf Spot Tolerance
Organic Hybrids
NC+ 69R36 115 8 6 7 6 5 7
NC+ 62N37 111 7 7 6 7 4 8
NC+ 68F32 112 7 6 6 7 4 7
NC+ 60N37 109 8 6 9 5 4 8
Doeblers N509 103 8 9 9 7 5 7
Doeblers N640 111 7 7 8 8 4 8
Untreated Conventional
Pioneer 34K77 107 7 6 6 7 4 7
Pioneer 34B97 108 6 6 6 6 5 7
Pioneer 3394 110 8 8 6 5 2 7
Pioneer 33G26 112 7 8 7 5 5 7
Pioneer 33M54 114 5 5 6 7 6 7
Pioneer 32R25 114 6 5 4 4 3 8
Syngenta N65- M7 109 5 6 6 4 6 8
Syngenta N79- L3 115 7 7 7 4 4 6
Augusta A- 4587 116 5 5 7 6 4 7
* Ratings are based on a scale of 1 to 10. A rating of 10 represents a plant with complete resistance or tolerance to dis-ease
or stress.
Figure 3- 1. Sample planting pattern for a strip test.
New Standard New Standard New Standard New Standard
Hybrid 1 Hybrid Hybrid 2 Hybrid Hybrid 3 Hybrid Hybrid 4 Hybrid
8 North Carolina Organic Grain Production Guide
Planting Date
Planting date is a crucial factor in the success of an
organic production system. Planting too early results
in slow growth and increases the amount of weed
competition, the incidence of seedling diseases, and
the likelihood of damage from seedling insects. On
the other hand, planting too late results in a greater
risk of drought stress, increased insect damage from
second and third generations of European corn bor-ers,
and reduced yield from a decrease in intercepted
sunlight due to decreasing hours of daylight. The
recommendations here attempt to balance these con-siderations.
In the tidewater and coastal plain,
plant organic corn between April 15 and May 15. In
the piedmont, plant organic corn between April 20
and May 20. In all locations, plant following at least
two days when average temperatures are above 65 º F.
Depending on the soil type, time soil preparation
and planting date so that soils are moderately dry at
planting to minimize the risk of seedling diseases.
Seedbed Preparation and Planting Depth
Seedbed preparation should begin with a major till-age
operation performed at least a month before
planting. If cover crops are used, they may need to
be killed and/ or incorporated into soils earlier than
one month before planting to allow for residue de-composition
and to avoid seed corn maggots. Heavy
applications of compost or manure should also be
incorporated earlier. Follow up with at least two
light tillage operations to create a smooth, weed- free
seedbed. The final tillage operation should be per-formed
on the day of planting to ensure that all ger-minated
weeds have been destroyed when the seed
is placed in the ground. The seed should be placed
exactly 1 inch deep, and the soil compressed to pro-vide
maximum seed- soil contact for rapid germina-tion
and growth. Seeding depth is a very important
factor in an organic production system. Seeds
planted too deeply will be slow to emerge, and seed-lings
will have immediate weed competition and a
greater likelihood of damage caused by seedling
diseases.
Plant Population
Plant population is another important factor in or-ganic
corn production, especially when corn is
grown on sandy soils. Plant populations should be
related to the moisture- holding capacities of each
individual field. In organic systems, corn plant
populations per acre should be 10 percent higher
than populations in conventional systems. The
higher plant population will increase light intercep-tion
and reduce weed competition and the effects of
pest damage. On soils with good- to- excellent water-holding
capacity, the goal is a stand of 30,000 to
33,000 plants per acre; on soils with average water-holding
capacity, 25,000 to 28,000 plants per acre;
and on soils with poor water- holding capacity, no
more than 22,000 plants per acre.
Row Spacing
Narrow rows permit more uniform plant distribution
and result in rapid closing of the canopy. In choosing
a row width, balance the potential advantages that
come from narrower rows against the additional
machinery cost and management that a narrow row
system demands. Because cultivation is the primary
weed control measure in organic production, make
row widths wide enough to permit the use of a trac-tor-
mounted cultivator. Where weeds are not a major
problem, use row spacing of 20 to 24 inches. Where
weed control will require multiple passes of a culti-vator,
use row spacing of 30 to 36 inches.
Soil Fertility
Corn generally requires from 120 to 160 pounds
of nitrogen per acre, 30 to 50 pounds of phospho-rus
per acre, 80 to 100 pounds of potassium per
North Carolina Organic Grain Production Guide 9
acre, and smaller amounts of sulfur and micronu-trients
to obtain optimum yield. Organic corn
growers should design their systems so that the
amount of nutrients added to the system offsets
the amount removed in the grain or forage. The
local offices of the USDA Natural Resources Con-servation
Service, the Cooperative Extension Ser-vice,
or the Soil and Water Conservation District
can provide guidelines for a nutrient management
plan. Chapter 6 in this manual also has more in-formation
on organic soil management.
Weed Management
Grassy weeds and warm- season broadleaf weeds,
such as cocklebur and morningglory, will be among
the most difficult to control. While tillage prior to
planting can help reduce early- season weeds, many
of the summer annuals will continue to germinate
and grow. It is very important to start with a clean
seedbed and to till the soil just prior to planting so
that the crop begins with a head start on new weed
seedlings. This will make it much easier to use culti-vation
to control grass and broadleaf weeds that are
smaller than the corn.
It is also important to take advantage of the
ability of the corn canopy to shade the soil. Shade
reduces the number of weeds germinating and
slows their growth. Use of increased plant popula-tions,
narrower rows, row directions perpendicu-lar
to the path of the sun, and tall- growing hybrids
all increase canopy density and lead to quick
canopy closure.
Remember that weed competition during the
first four to six weeks after planting will cause the
most damage in terms of yield reductions. Weeds
that emerge after canopy closure will have little
effect on yield, although they can make harvest
more difficult. Chapter 7 in this manual has more
information on managing weeds in organic pro-duction.
Insect Pest Management
Cultural practices are very important for estab-lishing
a vigorous, full corn stand. Stand estab-lishment
can greatly influence pest populations as
well as crop competitiveness and tolerance to pest
feeding. In fields where pests are historically at
high levels, do not plant organic corn if suitable,
effective, and economical pest management op-tions
are not available.
Crop rotation
Crop rotation is the most powerful tool for insect
management and is also often the lowest- cost
method of control. Rotations of at least two years
and use of a nongrass crop will reduce the levels of
many pests through starvation, interference with
insect reproduction, or both. Rotation also gives the
option of isolating corn crops from one year to the
next. Rotation in large units with a minimum of 800
to 1,000 feet between current and previous corn is
the most effective way to manage moderately mobile
pests such as billbugs.
Control of insects with tillage
Insect pests that feed on seed and small seedlings
are typically found in the soil or at the soil sur-face.
Populations of wireworms, cutworms, grubs,
seed corn beetle, and other pests can be reduced
with winter or early spring disking and the ac-companying
bird feeding and exposure. The com-bined
action of these factors can give meaningful
protection to planted seed and small seedlings. In
organic corn production, no- till should be avoided
or used with caution, especially in areas where
southern corn billbug, wireworms, and cutworms
are common.
Rapid germination and seedling grow- off
Rapid germination and seedling grow- off reduces the
time corn seed and seedlings spend in the most vul-nerable
stage between germination and the six- leaf
10 North Carolina Organic Grain Production Guide
stage and helps the crop gain a size advantage over
weeds. Losses to seedling insects and other pests can
be reduced by promoting early germination through
row- bedding, seeding at the recommended depth,
hybrid selection for performance under cool condi-tions,
and adequate soil fertility.
Crop maturity
In corn, timely maturity of the crop almost always
reduces insect damage. Certain pest insects and
pathogens ( for example, late- season corn borers
and fall army worms) reach high levels in late
July and August and may severely infest late-maturing
corn. Timely planting and avoidance of
late- maturing hybrids ( over 120 days) will reduce
the level of pests attracted to the crop in late- sea-son
and prevent yield loss. When planted early,
hybrids that mature in 112 days or less will usu-ally
avoid late- season caterpillar attack.
Hybrid selection
Rapid germination, early vigor, strong ear shanks,
tight husks, resistance to stalk rots and other
pests, strong stalks, and uniform performance
over a wide population range are factors influ-enced
by genetics that may reduce losses to in-sects.
Some hybrids have European- corn- borer-resistance
traits that will reduce susceptibility to
this important pest.
Major Corn Insect Pests and
Management
Corn billbugs
Billbugs can be serious pests of corn seedlings.
No insecticide approved for organic use has activ-ity
against billbugs. Combining cultural tactics—
rotation and isolation from previous corn crops—
along with rapid seedling emergence and grow- off
should help prevent concentrations of adult bill-bugs
and promote rapid accumulation of toler-ance.
Three additional billbug management tactics
are ( 1) avoiding areas with abundant nutsedge,
which is an alternative host for billbug; ( 2) avoid-ing
no- till production for organic corn because
no- till soils warm more slowly and delay germi-nation
and grow off; and ( 3) planting at the earli-est
possible date to allow seedling growth prior to
billbug adult emergence.
Wireworm and black cutworm
In organic systems, the major tactics for reducing
populations of these insects will be disc cultivation
and avoidance of no- till situations. Cultural methods
that promote rapid seedling growth and seeding at
adequately high populations to allow some seedling
loss can also be important.
European corn borer ( ECB) and southern corn-stalk
borer
Borers occur in all North Carolina corn fields. Their
populations fluctuate greatly between years and
sometimes within a single growing season. The or-ganic
farmer can influence the abundance of these
borers through rotation, site selection ( away from
first- generation ECB nursery areas in white potato
and wheat fields), early planting, use of short- season
corn hybrids, and selection of hybrids with ECB
tolerance. Taking these actions to manage both space
and time will help avoid high populations and pro-mote
tolerance for those borers that are present. Or-ganically
approved spinosad insecticides are labeled
for ECB on corn, but they are expensive and are not
likely to be effective when sprayed on tall corn. For
ECB scouting procedures and thresholds, consult
your county Extension office or the following Web
site: http:// www. ces. ncsu. edu/ plymouth/ pubs/ ent/
index1. html.
Western corn rootworm
Western corn rootworm is a pest only in nonrotated
corn. It can be successfully managed in an organic
system by rotating corn with other crops.
North Carolina Organic Grain Production Guide 11
Key Diseases and Management
Three key diseases— seed rots and seedling blights,
stalk rots, and charcoal rot, which are usually con-trolled
in conventional systems either by fungicides
or management practices— can have significant im-pacts
on organically grown corn. Growers should be
aware of these diseases and select hybrids and man-agement
practices that reduce the risk they pose.
While there are many other diseases that can attack
corn, they rarely cause economic loss. Pictures of
these field corn diseases can be found at this Web
site: http:// www. btny. purdue. edu/ Extension/ Pathol-ogy/
CropDiseases/ Corn/.
Seed rots and seedling blights
Seed rots and seedling blights caused by species of
Fusarium, Stenocarpella, Pythium, and other fungi
are often associated with the term “ damping- off.”
Plants die at emergence or within a few days of
emergence. These diseases are more prevalent in
poorly drained, excessively compacted, or cold, wet
soils. Planting old or poor quality seed with mechanical
injury will increase seed rot and seedling blight, as will
planting seed too deep in wet, heavy soils. Seed vigor
ratings are often used to select hybrids with genetic
resistance to seed rots and seedling blight.
Stalk rots
Stalk rots ( caused principally by the fungi
Stenocarpella zeae and species of Fusarium as well as
Colletotrichum graminicola) are present each year and
may cause considerable damage, particularly if abun-dant
rainfall occurs during the latter part of the growing
season. Stalks previously injured by cold, leaf diseases,
or insects are especially susceptible to attack by these
fungi. Diseased stalks ripen prematurely and are sub-ject
to excessive stalk breaking. Stalk rots not only add
to the cost of harvesting but also bring the ears in con-tact
with the ground, increasing their chance of rotting.
Adequate fertility ( particularly adequate potassium) is
the key to controlling stalk rot.
Charcoal rot
Charcoal rot ( caused by the fungus Macro- phomina
phaseolina) becomes most evident with the onset of
hot dry weather. It may cause stalk rot, stunting, and
death of the corn plant. This disease is often considered
to be stress related. Typically, when this disease occurs
in North Carolina, soil fertility and pH are at very low
levels. Although the fungus survives in the soil, rota-tion
is not generally helpful since most crops are sus-ceptible
to this disease. Supplying adequate nutrition
and water is the principal means of control. Hybrid
resistance in corn has not been documented.
Harvesting
Early harvesting usually avoids crop damage from
pests or hurricanes and prevents field losses re-sulting
from ear drop and fungal pathogens. Prob-ably
the most important reason for timely harvest
is the potential for yield reductions resulting from
ear loss and ear rots due to stalk lodging, ear
drops, and reductions in kernel weight. Fungal
diseases that infect the corn kernel also cause
more problems as harvest is delayed. Mycotoxins,
such as aflatoxin and fumonisin, which are pro-duced
by fungal pathogens, also increase as har-vest
is delayed and may result in corn that is un-suitable
for human or livestock consumption. Ide-ally,
corn harvest should begin as soon as the
grain reaches moisture levels of 25 percent or
less. Under favorable conditions, corn should be
ready to harvest in 10 days or less following the
black layer formation at the base of the kernels.
12 North Carolina Organic Grain Production Guide
Chapter 4. Crop Production
Management— Organic Wheat
and Small Grains
Randy Weisz, Crop Science Extension Specialist, NC State
University
John Van Duyn, Entomology Extension Specialist, NC State
University
Production Management
Key management practices for organic wheat and
small grain production:
• Choose varieties with resistance to disease and
insect pests.
• Plant on time ( not too early, not too late) in a
well- prepared seedbed.
• Implement crop rotation.
• Use correct drill calibration and operation.
• Avoid excessively high nitrogen levels ( but
work towards good soil fertility).
• Destroy crop residues with tillage, if possible.
Variety Selection
As a general rule, only small grain varieties that
have been successfully grown in the North Caro-lina
Small Grain Official Variety Test for two
years should be considered for production. Offi-cial
Variety Test reports are available online at
http:// www. smallgrains. ncsu. edu or from your
county Extension center. It is nearly impossible to
pick a single best variety. Consequently, produc-ers
should plant two or more varieties every sea-son
in order to reduce their risks and maximize
the potential for a high- yielding crop. The follow-ing
are general guidelines for selecting varieties
for organic wheat production:
• Check the Official Variety Test Report for a list
of varieties tested for at least two years.
• To avoid spring freeze injury, eliminate early-heading
varieties in favor of medium- and
late- heading varieties.
• If powdery mildew is common in your area,
select varieties that are rated as “ good” for
powdery mildew resistance.
• If you are a producer in the tidewater area,
select varieties that have “ good” or “ fair”
resistance to leaf rust.
• If possible, avoid varieties that are rated “ poor”
for Hessian fly biotype- L.
• If wheat is being produced for the baking in-dustry,
it is a good idea to check variety selec-tion
with the end user.
Planting Date
Not too early and not too late! Planting too early
puts the crop at severe risk for powdery mildew,
Hessian fly, aphids, and barley yellow dwarf virus.
Planting too late will reduce yields, increase the risk
of having a winter annual weed problem, and result
in thin stands that will attract cereal leaf beetles. For
the optimum planting times for your region, see the
most recent edition of the Small Grain Production
Guide or go online to http://
www. smallgrains. ncsu. edu/ Guide/ Chapter7. html.
Rotation and Field Selection
Planting wheat into old wheat stubble is always a
bad idea. Several major small grain diseases and
Hessian fly are vectored on old wheat stubble. Short
rotations put small grains at high risk to numerous
soilborne diseases and should be avoided in organic
production. Additionally, as described in more detail
below, the best way to avoid a Hessian fly problem
North Carolina Organic Grain Production Guide 13
is to plant at least one field ( or ¼ - mile) away from
last year’s wheat stubble and to avoid planting near
an early- planted wheat cover crop. Fields with a
history of Italian ryegrass, wild garlic, wheat spindle
streak, or wheat soilborne mosaic virus should be
avoided.
Drill Calibration and Operation
A good stand of wheat is the best defense against
weeds and cereal leaf beetle and is the best indicator
of a high yield potential. A complete guide to seed-ing
rate, drill calibration, planting depth, and other
planting considerations can be found in the most
recent edition of the Small Grain Production Guide
or go online to http:// www. smallgrains. ncsu. edu/
Guide/ Chapter6. html.
Soil Fertility
Wheat that yields 40 bushels per acre uses about 50
pounds of nitrogen per acre, 25 pounds of phosphate
per acre, and 15 pounds of potash per acre. Wheat is
a moderately heavy feeder, but not as heavy as corn.
For best yield results, an organically approved nitro-gen
source ( such as manure, compost, or a tilled- in
legume ) should be added at or before planting and
again in the spring. See Chapter 6 of this guide for
more information on soil fertility in organic produc-tion.
In early spring, it is possible to test a wheat
crop and determine how much additional nitrogen it
needs to produce optimal yield. Organic growers
may want to use tissue testing to determine whether
the crop needs additional spring top- dress nitrogen.
Weed Management
Essentially all weed control in organic wheat must
be achieved in seedbed preparation before planting.
Little to no cultivation is used in wheat after planting
to kill emerging weeds, but a rotary hoe or tine
weeder can be used before the crop emerges if
needed. However, weeds usually cause fewer prob-lems
in wheat than in corn or soybeans because
wheat is a strong competitor against weeds and is
drilled in narrow rows that quickly shade the soil.
Most wheat drills are set to plant rows that are 6 to 8
inches apart. Organic producers may want to take
advantage of row spacing as narrow as 4 inches to
help the wheat outcompete winter annual weeds.
Avoid planting organic wheat in fields with Italian
ryegrass or wild garlic problems as these weeds can
lead to quality problems in the harvested grain. Also,
use caution with hairy vetch as a cover crop in fields
where wheat will be planted because hairy vetch that
reseeds can contaminate wheat grain with seeds that
are similar in size and weight and that are difficult to
separate. See Chapter 7 for more information on
weed management in organic production systems.
Insect Pest Management
Wheat fields are susceptible to many kinds of in-sects.
Only a few species may become pests, and
even when they do, they usually do not reach dam-aging
above- threshold numbers. However, in some
seasons or under certain circumstances, insect pests
of wheat can be very damaging. The following in-sects
may become abundant enough to cause signifi-cant
injury to wheat crops in North Carolina: aphids
( several species), cereal leaf beetle, Hessian fly, and
armyworm ( sometimes called true armyworm).
Other plant- feeding insects, such as grasshoppers,
chinch bugs, or fall armyworms, may occasionally
damage wheat. Descriptions of all these insects may
be found in the most recent edition of the Small
Grains Production Guide, at county Extension cen-ters,
or at the following Web sites:
http:// www. ces. ncsu. edu/ plymouth/ pubs/ ent/ index4. html
http:// www. smallgrains. ncsu. edu/ Insects/ Insects. html
Wheat- feeding aphids
Three primary species of aphids occur in North
Carolina wheat: the English grain aphid, the bird- oat
cherry aphid, and the corn leaf aphid. Aphid feeding
14 North Carolina Organic Grain Production Guide
potentially reduces yield, but usually not dramati-cally.
Aphids are also vectors of barley yellow dwarf
virus ( BYDV), and this disease can be a serious con-cern.
A complex of biological control agents accom-panies
aphids, including parasites, predators, and
pathogens ( mainly fungi). These biological control
agents ordinarily exert a powerful controlling influ-ence
on aphid populations, especially in the spring,
although it usually requires some time before the
aphid populations “ crash” due to the combined influ-ence
of these agents.
Several cultural practices can help reduce the
chance of aphid damage and BYDV infection in
organic production:
Avoid early planting. Cool weather will slow
aphid feeding and activity in the newly emerged
crop. Planting after the end of warm weather not
only reduces the chance of crop damage due to
aphid feeding, but also makes it less likely that
aphid- transmitted BYDV infections will occur.
The aphid population may build up again in the
spring, but these populations are less damaging
because plants are larger, growing more rapidly,
and are more tolerant to feeding and BYDV infec-tion.
Avoid excessively high soil nitrogen levels.
Aphids reproduce most rapidly on plants with high-nitrogen
content. Maintaining nitrogen levels within
the prescribed agronomic level ( found in the most
recent edition of the Small Grain Production Guide)
helps to avoid high aphid populations.
Select wheat varieties with BYDV resistance. If
BYDV is a regular problem on your farm or on
neighboring farms, a highly effective strategy is to
select wheat varieties that are resistant to this dis-ease.
A list of wheat varieties and their resistance to
BYDV can be found at this Web site:
http:// www. smallgrains. ncsu. edu/ Varieties/
Varieties. html
Armyworm
Armyworm moths are one of a few moths active in late
winter and early spring. Armyworm caterpillars may
cause serious defoliation and substantial head drop.
They are most prevalent in the northeastern counties of
North Carolina.
Management options. Few cultural management
options are available for armyworm. Organic grow-ers
have the choice of accepting the feeding of army-worms
or using an insecticide approved for organic
production ( such as a spinosad) in emergency situa-tions.
Accepting the feeding of armyworm is not
likely to result in large yield losses unless plants
were defoliated early ( before or during the heading
period). For scouting information on armyworm,
check the most recent edition of the Small Grain
Production Guide or go online to http://
www. smallgrains. ncsu. edu/ Guide/ Chapter11. html.
Cereal leaf beetle
The cereal leaf beetle ( CLB) has one generation each
year, and both the adult and larval stages eat leaf
tissue on wheat and oats. They do not feed on barley,
triticale, or rye. Leaf feeding by larvae during April
and May can reduce yields.
Cereal leaf beetle is an introduced pest, and few
native biological control agents affect adult beetles,
eggs, or larvae. A few generalist predators, such as
lady beetles, appear to consume cereal leaf beetle
eggs and, perhaps, young larvae in early spring. The
North Carolina Department of Agriculture has re-leased
several species of exotic parasites throughout
the state. These parasites develop within cereal leaf
beetle eggs or larvae and have the potential to keep
populations below an economic level. Parasite re-lease
programs have worked well in several other
states, but so far have had limited success in North
Carolina.
Cultural practices. Cereal leaf beetles prefer to
attack a thin field full of little plants rather than a thick,
lush field full of large, healthy wheat. To minimize the
chances of beetle invasion, the organic producer needs
to do everything possible to assure a thick, well tillered,
healthy crop. This means good seed bed preparation,
planting on time, using high quality seed, correct drill
calibration, and getting good soil- seed contact at the
proper seeding depth. These steps will also increase the
crop’s tolerance to CLB feeding.
North Carolina Organic Grain Production Guide 15
Insecticides. Insecticides approved for organic
production ( such as a spinosad) and labeled for ce-real
leaf beetle may be applied in emergency situa-tions.
For scouting information for cereal leaf beetle,
check the most recent edition of the Small Grain
Production Guide or go online: http://
www. smallgrains. ncsu. edu/ Guide/ Chapter11. html.
In addition, a special publication on this pest can be
found at http:// www. ext. vt. edu/ pubs/ entomology/
444- 350/ 444- 350. html.
Hessian fly
In recent years, Hessian fly infestations have caused
extensive losses in many North Carolina fields. Or-ganic
farmers should use several methods to mini-mize
Hessian fly problems.
Rotation. Because the Hessian fly life cycle
depends largely upon the presence of wheat stubble,
using rotations that do not plant new wheat into or
near a previous wheat crop’s stubble will be the most
effective way to prevent infestations. Additionally,
since the Hessian fly is a weak flier, putting at least
one field ( or about ¼ - mile) between new wheat
plantings and the previous season’s wheat fields can
be a successful method of preventing new infesta-tions.
Tillage. Disking wheat stubble after harvest
effectively kills Hessian fly. Burning is not as effec-tive
as disking. Although burning wheat straw will
reduce populations, many pupae will survive below
the soil surface.
Careful use of cover crops. Serious Hessian fly
infestations have occurred in areas where wheat for
grain was planted near early- planted wheat for cover
or early- planted wheat for dove hunting purposes. In
organic systems using cover crops, selecting a small
grain other than wheat will reduce Hessian fly popu-lations.
Oats, rye, and triticale are not favorable for
Hessian fly reproduction and do not serve as a nurs-ery.
Plant on time. Do not delay planting until after
the first freeze ( often called the fly- free date) be-cause
an early freeze in North Carolina is not a de-pendable
event. Often a “ killing freeze” does not
occur until December in many areas of North Caro-lina,
which is later than most growers need to have
wheat planted for agronomic purposes. Organic pro-ducers
throughout North Carolina should also avoid
planting before the recommended planting dates.
Resistant varieties. Many wheat varieties are
advertised as having Hessian fly resistance. To be
effective in North Carolina, however, wheat varieties
must be specifically resistant to Hessian fly biotype-
L. A list of wheat varieties with biotype- L resistance
can be found on the Internet at http://
www. smallgrains. ncsu. edu/ or through county Ex-tension
offices. For more information on Hessian
Fly, see The Hessian Fly: A Pest of Wheat in North
Carolina ( AG- 368), which is available online:
http:// www. ces. ncsu. edu/ depts/ ent/ notes/ Grain/ Hes-sian/
HflyAG- 368. html.
Disease Management
Disease identification
The first step in solving disease problems is to iden-tify
the disease. Excellent small grain disease infor-mation
and assistance with disease identification can
be found in the latest edition of the Small Grains
Production Guide or on the Web at http://
www. smallgrains. ncsu. edu/ Diseases/ Diseases. html.
Varieties are rated for disease resistance at http://
www. smallgrains. ncsu. edu/ Varieties/ Varieties. html.
Barley yellow dwarf virus
Barley yellow dwarf virus ( BYDV) is the most im-portant
viral disease of wheat, oats, barley, and rye
in this state. The virus is transmitted by aphids that
spent the summer on nearby corn crops or host
grasses. The best control measure in organic produc-tion
is to plant varieties that are resistant to this dis-ease.
Powdery mildew
One of the most yield- limiting factors in North Caro-lina
wheat production is powdery mildew. This is
especially true in the coastal plain, the southern pied-mont,
and some tidewater areas. Conventional pro-
16 North Carolina Organic Grain Production Guide
ducers often do not consider powdery mildew in
their planning because they can rely on foliar fungi-cides
to control the disease if it occurs. Organic pro-ducers
do not have that luxury.
Select resistant varieties. The best protection
against powdery mildew is to select wheat varieties
that are resistant to it. Organic producers who want
high- yielding wheat must plant powdery- mildew-resistant
varieties. Wheat varieties grown in North
Carolina are evaluated for disease resistance every
year, and new disease- resistance ratings are pub-lished
in the Small Grains Official Variety Test Re-sults
and posted on the Internet every July in time
for growers to order the best varieties for the next
year’s production. Organic producers should check
the Web site http:// www. smallgrains. ncsu. edu/ Variet-ies/
Varieties. html every year ( or contact the county
Extension agent for the information) and use the list
of the most resistant varieties as a starting point for
ordering seed.
Adjust planting date. A second defense against
powdery mildew is to plant after the weather has
turned cold. This decision involves a trade- off. Al-though
powdery mildew does not grow in cold
weather, neither does wheat. This means that late-planted
wheat may avoid powdery mildew, but it is
also likely to suffer from lower yields and attack by
cereal leaf beetle. However, organic producers, espe-cially
those in the coastal plain, southern piedmont,
and tidewater region, should also avoid planting
before the recommended planting dates.
Leaf rust
Leaf rust is a foliar disease that attacks wheat late in
the growing season. While leaf rust can occur any-where
in North Carolina, it is most likely to be a
problem in the tidewater. Conventional producers
rely on foliar fungicides to protect the crop from this
disease. Organic producers must select varieties with
good resistance to leaf rust. Organic producers, espe-cially
those in the tidewater, should try to select vari-eties
that have a combination of powdery mildew
and leaf rust resistance. Variety resistance to leaf rust
also deteriorates from year to year, so organic pro-ducers
should check the most recent variety ratings
every year before ordering seed.
Loose smut
Loose smut symptoms occur between heading and
maturity. Infected seed appears normal. The fungus,
which is found inside the embryo of the seed, will
grow within the plant from germination until the
seed heads emerge and smutted grains appear. There-fore,
symptoms from an infection that occurs in one
year will not be seen until plants from the infected
seed mature in another year. Because loose smut is
seedborne, control measures focus on the seed to be
planted. Certified seed fields are inspected for loose
smut, and strict standards are enforced. Seed from
fields with loose smut are rejected. Therefore, using
certified seed is a highly effective way to avoid loose
smut. Organic producers who use farmer- saved seed
should never plant seed from a crop infected with
loose smut.
Septoria leaf and glume blotch
Septoria leaf and glume blotch may occur at any
time during the growth of the plant and on any por-tion
of the plant. Rotation away from small grains
for at least three years can lessen the severity of
septoria. Plowing under wheat stubble will prevent
infection from the previous wheat crop. Potash, cop-per,
and magnesium should be kept at recommended
levels. In some cases, septoria can be seedborne, so
certified seed can reduce introduction of the disease.
Organic farmers should never save seed for planting
if the wheat was infected with septoria.
Scab or head blight
Scab, a fungus that is seen as prematurely bleached
heads or spikelets, can occur in all small grains. Of
the small grains, wheat and barley are the most sus-ceptible
to this disease, and rye and triticale are the
most resistant. Scab occurs and is spread to small
grains in the spring. It also results in toxins
( vomitoxin is most common) in the harvested grain.
The first line of defense against scab is to plant
wheat varieties with resistance to the fungus. A com-
North Carolina Organic Grain Production Guide 17
plete list of wheat varieties and their resistance to
head scab can be found at http:// www. smallgrains.
ncsu. edu or at county Extension centers. Wheat pro-ducers
with a history of scab should seriously con-sider
selecting varieties based on this information.
Tillage practices that bury wheat or corn residues
and rotations of at least three years are effective
means of controlling scab in organic production.
Planting several wheat varieties with different head-ing
dates will stagger head emergence and flowering
through the spring and reduce the chance that envi-ronmental
conditions will be suitable to scab in all
wheat fields.
If scab is present, the combine may be adjusted
so that the lightweight diseased grain is removed
along with the chaff. This will not remove all the
infected grain, but can help reduce mycotoxin levels
in the grain going to market. Organic producers
should never use farmer- saved seed if head scab was
present in the crop that produced the seed.
Other small grain diseases
Several other diseases can be problems for small
grain in North Carolina. Growers in need of more
detailed information should check online at http://
www. smallgrains. ncsu. edu or with their county Ex-tension
agent.
Avoiding Spring Freeze Injury
Late spring freeze damage is a major factor in reduc-ing
yields of North Carolina wheat. “ Heading date”
is an important indication of how susceptible a vari-ety
will be to late spring freeze damage. Early- head-ing
varieties are the most susceptible to freeze dam-age.
Medium- and late- heading varieties are more
likely to avoid spring freeze damage, and they gener-ally
produce higher yields than early- or medium-early
heading varieties. Heading date also indicates
the best planting date for a wheat variety. Medium-and
late- heading wheat varieties tend to do best
when planted at the start of the planting season, and
should be the first varieties planted. Early and me-dium-
early varieties tend to produce the highest
yields when planted later in the fall. Wheat variety
heading date information can be found online: http://
www. smallgrains. ncsu. edu/ Varieties/ Varieties. html.
18 North Carolina Organic Grain Production Guide
Chapter 5. Crop Production
Management— Organic Soybeans
Jim Dunphy, Crop Science Extension Specialist, NC State University
John Van Duyn, Entomology Extension Specialist, NC State University
Production Management
Key management practices for organic soybean pro-duction:
• Choose varieties that perform well in your area
( selecting earlier or mid- season maturity
groups, if possible).
• Plant on time ( not too late).
• Adjust equipment for a high plant population.
• Rotate crops.
• Plant in narrow rows.
Variety Selection
Choosing a soybean variety also means choosing a
Maturity Group. In organic production, an earlier-maturing
( Maturity Group V for most of North Caro-lina)
or mid- season variety ( Maturity Group VI) is
preferred over late- maturing varieties ( Group VII or
later). Early- maturing beans can avoid hurricane
winds and moisture and associated disease problems
and yield losses. Because of soil type and more fre-quent
rains, the blacklands of North Carolina can use
an earlier- maturing bean ( Group V or earlier) without
yield loss. However, farther west and on sandier soils, a
later- maturing variety ( Group VI or later) may be
needed to get adequate yields. In the coastal plain, a
Group VI or late V ( or an earlier planting) will help
avoid corn earworm ( CEW) infestation during flower-ing.
CEW is seldom a problem in the piedmont. Variety
selection is also an excellent way to deal with nema-tode
problems. Selecting varieties that are resistant to
the species and race of nematode present in the field
can limit the yield loss caused by these pests. It is also
a good idea to choose at least two different varieties in
order spread out the seasonal workload and risk. The
Official Variety Test Report available at
www. ovt. ncsu. edu or through your county Extension
center is a good source of information on varieties.
Unfortunately, there are fewer and fewer conven-tional
or nontransgenic varieties available on the
market. Organic farmers must be aware that
transgenic beans are not allowed in certified organic
production, and choose alternate varieties. Table 5- 1
lists top- yielding non- GMO, feed- grade varieties in
North Carolina through 2004, as noted by J. Dunphy
in North Carolina Soybean Variety Information
( 2005, Extension publication CS- SB- 15).
Planting Date
Planting date and variety ( or maturity group) selection
go hand- in- hand. The key is to match planting date and
variety maturity to the soil so that the row middles are
lapped with soybean plants about 3 feet tall by flower-ing
time. Planting earlier or planting a later- maturing
variety can improve the likelihood of achieving this. In
an organic farming system, avoiding pest problems is
an important management technique. Planting early ( by
the end of May) with an early to mid- season variety
can help the crop avoid insect and disease problems.
Row Spacing
Soybeans in row widths of 20- inches or less tend to
have higher yields than soybeans in wider row
widths. Narrow- row soybeans also lap the row
middles sooner, making further weed control mea-sures
during the season unnecessary.
Plant Population
Weeds are the main pest that organic soybean pro-ducers
are going to face, and a thick plant population
North Carolina Organic Grain Production Guide 19
will compete with weeds more effectively. Thicker
populations have denser, earlier- closing canopies
that out- compete weeds and do not allow enough
light to penetrate for weed seed germination. How-ever,
a thick plant stand also traps moisture in the
canopy, which creates a good environment for dis-ease.
A good compromise is needed, but a closed
canopy is preferred. Although it increases the risk of
disease, it is also the best way to maximize yields.
An ideal stand would have plants that are about 3
feet tall with row middles lapped by the time of
flowering. Plant population in the field can vary
widely and still achieve good yields. On 36- inch
rows with a May planting date, an ideal plant popu-lation
would be 6 to 8 plants per foot ( about 100,000
plants per acre). In 20- inch rows, the recommended
plant population is still 100,000 plants per acre, but
the plant population per foot will be lower. If plant-ing
on 7- inch rows, 2 plants per foot ( 150,000 plants
per acre) can achieve good yields. Seeding rate will
depend on the planter calibration, seed germination,
and soil condition. Proper calibration of the planter
is important, as well as planting in ideal soil condi-tions
( the soil should be warm and moist, but not
wet). If planting in June, increase these seeding rates
by 20 percent.
Soil Fertility
Soybeans yielding 50 bushels per acre will remove
about 188 pounds of nitrogen per acre, 41 pounds of
phosphate per acre, and 74 pounds of potash per acre
from the soil. However, manure and compost appli-cations
are usually unnecessary because soybeans
are nitrogen- fixing legumes and the crop can make
use of any nutrients applied to, but not removed by,
previous crops. If soybeans were not grown in previ-ous
years, soybeans should be inoculated with spe-cies
of Bradyrhizobium bacteria specific for soy-beans.
Inoculums must not be genetically engi-neered.
See Chapter 6 of this guide for more infor-mation
about organic soil management.
Table 5- 1. Nontransgenic soybean varieties, relative
yield over all locations, number of locations and years
in variety trial.
Percent +/- No. First Last
Variety Average* of sites year year
Maturity Group IV
DP 4748 S - 13.0 2 2000 2000
Maturity Group V
5002T - 2.9 6 2003 2004
5601T - 3.1 13 2001 2004
95B33 - 5.1 14 2000 2001
AP 572STS - 8.9 8 2000 2000
Bolivar - 2.3 4 2004 2004
DP 5110 S - 6.3 22 2000 2004
DP 5989 - 4.0 22 2000 2002
Fowler - 3.5 28 2000 2004
Freedom - 16.2 4 2004 2004
HBK C5894 - 3.1 4 2004 2004
Hutcheson - 4.3 35 2000 2004
Ozark - 11.8 4 2004 2004
SS 5200- STS - 17.0 16 2001 2003
SS 597 2.4 15 2000 2001
Teejay 8.4 4 2004 2004
USG 550nSTS - 14.0 13 2002 2004
Maturity Group VI
665 6.4 25 2000 2003
Boggs - 13.0 8 2004 2004
Dillon 2.5 29 2000 2004
HBK 6600 - 8.0 8 2000 2000
NC- Roy 9.7 29 2000 2004
Satelite - 9.7 22 2000 2002
Soyola - 0.1 25 2000 2003
Maturity Groups VII and VIII
Cook 3.8 15 2000 2004
N7001 0.6 18 2000 2004
N7102 - 21.5 4 2002 2002
N7103 - 8.7 8 2000 2002
NC- Raleigh 12.1 18 2000 2004
* Percent above (+) or below (-) average yield of all varieties of the
same maturity group at the same locations in NC Official Variety
Tests ( OVT) in 2000 through 2004.
20 North Carolina Organic Grain Production Guide
Weed Management
Organic weed management is more challenging in
soybeans than in corn since the soybean foliage does
not generally overlap and shade the row middles until
later in the season. Generally, narrow rows and in-creased
plant population can help the crop compete
more effectively against weeds. When managing weeds
in soybeans, consider also that different planting times
for soybeans result in the plants competing against
different sets of weed species. Weeds that emerge dur-ing
the first four to five weeks after planting will cause
the most damage in terms of yield reductions. Weeds
that emerge after this time will have little effect on
yield, although they may make harvest more difficult
and will set seed. The goal should be to keep the field
clean through the first four to five weeks after planting.
See Chapter 7 of this guide for more information on
managing weeds in organic production.
Insect Pest Management
Differences caused by variety selection, planting
date, cultural techniques, site, and season cause great
variations in soybean plant attractiveness to insect
pests. If organic soybean farmers recognize these
differences, they can manage the crop for reduced
insect pest numbers or, when this is not possible,
predict which fields are attractive and may need
more attention to prevent yield loss. The organic
soybean grower can normally rely on three factors to
limit insect damage: reducing soybean attractiveness
to pests, beneficial insects that reduce pest numbers,
and the plant’s ability to compensate for insect dam-age
( tolerance). Important tactics used to reduce
insect damage include the following five strategies:
Rotation
Rotation helps reduce levels of pests like soybean
colaspis and cyst nematode and often improves crop
health. Avoiding pests through rotation of at least two
years allows soybeans to tolerate the feeding of pests
that later move into the field.
Soil fertility and pH maintenance
Thin plant stands often have more corn earworms,
but good growth reduces attractiveness. Reducing
plant stress from low pH, poor fertility, or inadequate
moisture will enable plants to better tolerate insect
feeding.
Variety selection and early planting
High caterpillar populations can often be avoided by
early planting of an early- maturing variety ( such as
varieties from Maturity Groups III, IV, or V). These
plantings will bloom and harden- off before the corn
earworm moth flight from corn fields, and the plants
will be unattractive to the moths. Also, early matu-rity
can greatly reduce soybean looper, velvetbean
caterpillar, and late stink bug infestations. In rare
situations, stink bugs can be trap- cropped by early-maturity
fields, leading to greater damage.
Narrow rows
A complete canopy allows a higher level of biologi-cal
control by insect predators, parasites, and dis-eases.
Also, narrow- row soybeans seem to be less
attractive to egg- laying corn earworm moths.
Remedial control
Group V or later- maturing varieties that are planted
after late May can become infested by corn earworm
moths moving from corn. These moths produce pod-feeding
corn earworm larvae, and a high infestation
may reduce yield by as much as 50 percent. Also,
populations of leaf- feeding caterpillars ( green
cloverworm, soybean looper, and velvetbean cater-pillar)
may occasionally damage soybeans to above
threshold levels. These worms are usually very late-season
pests. In instances where caterpillar pests are
not avoidable, insecticides approved for organic
production, such as spinosads or Bacillus
thuringiensis ( Bt), may be successfully used. Scout-ing
and the use of thresholds will indicate which
fields are at risk. For scouting procedures for corn
earworm see this Web site: http:// www. ces. ncsu. edu/
plymouth/ pubs/ ent/ index3. html.
North Carolina Organic Grain Production Guide 21
Disease Management
Soybeans have very few disease problems. This
makes disease management in organic soybeans
relatively easy. Nematodes are the main soybean
disease agent in North Carolina. However, Asian
soybean rust is a possible problem, and, if
present, will require much more intensive man-agement
to make organic soybean production vi-able.
Nematodes
The best way to avoid nematode damage is to plant
varieties that are resistant to the nematode ( and race)
present in the field. These varieties can be found on
the Web site www. soybeans. ncsu. edu/ soyvar or from
county Extension agents. Conventional nematicides
are prohibited in organic agriculture. Crop rotation
of at least two years will probably help reduce soy-bean
cyst nematode populations, but is not as useful
when dealing with root knot nematode because it has
multiple host plants. If nematode damage is sus-pected,
collect samples from the field ( fall is the best
time) and send them to the NCDA& CS laboratory
( 1040 Mail Service Center, Raleigh, NC 27699-
1040, 919- 733- 2655) for nematode assays. They will
identify a nematode population and species, if it is
present. The Agronomic Division of NCDA& CS
also has nematode management and assay informa-tion
on their Web site: www. ncagr. com/ agronomi/
nemhome. htm.
Asian soybean rust
Asian soybean rust is a disease that has the potential
for causing severe economic damage in North Caro-lina
soybean crops. It must be considered when man-aging
for soybean disease. To manage soybean rust
potential in organic soybeans in North Carolina,
select early- maturity groups and/ or plant early to get
the plants out of the fields in time to avoid the rust
inoculum. Do not, however, create such an early-maturing
soybean crop that yields are reduced sub-stantially.
For more information on soybean rust, go to one
of these Web sites:
• www. usda. gov/ soybeanrust/ ( USDA site on
Asian soybean rust)
• www. ces. ncsu. edu/ depts/ pp/ soybeanrust/ ( Soy-bean
Rust Forecast Center at NC State Uni-versity)
• www. sbrusa. net ( USDA online soybean rust
tracking site)
• www. attra. ncat. org/ attra- pub/
asian_ soy_ rust. html ( Appropriate Technology
Transfer for Rural Areas document on pos-sible
organic treatments for Asian soybean
rust)
22 North Carolina Organic Grain Production Guide
Chapter 6. Soil Management
Carl Crozier, Soil Science Extension Specialist, NC State University
Keith Baldwin, Extension Specialist, NC A& T State University
David Howle, Assistant Professor, Clemson University
Soil Management and the Organic
Standards
In an organic farming system, rotation and tillage
practices must provide an appropriate seedbed and
pest control while minimizing erosion. Soil fertility
must be sustainable without application of prohib-ited
substances. Soil management practices must be
developed in consultation with the certifying agent
who judges compliance with organic standards, ap-proves
inputs, and specifies needed documentation.
Crop Rotation, Tilth, Fertility, and Pest
Management
Crop rotation is critical to the maintenance of soil
tilth ( physical condition), fertility, organic matter,
and as a preventive practice to minimize pest prob-lems.
No specific rotations are mandated, but sug-gested
crops to include are sods, cover crops, green
manures, and catch crops. The rotation adopted must
resolve any relevant problems with soil organic mat-ter
content, deficient or excess plant nutrients, soil
erosion, and pest management. Defining a rotation is
also a key component in designing soil sampling and
tillage management schemes. For short rotations
( two to three years), soil samples can be collected
once per rotation. For longer rotations, soil samples
may still need to be collected every two to three
years, preferably prior to planting the most inten-sively
managed crops.
Soil Fertility Management
Although crop nutritional requirements are the same
for organic and conventional farms, organic producers
need to be more creative due to the limitations on al-lowable
inputs. Soils throughout the Carolinas differ in
texture, organic matter, past erosion, and residual nutri-ent
contents. Periodic soil testing is the only way to
understand the current fertility level and maintain the
fertility status of each field. Plant tissue analysis can
also be used to verify soil fertility status, particularly
for nutrients not easily measured in routine soil tests
( nitrogen, sulfur, boron). With tissue testing, the appro-priate
plant part must be collected at the proper growth
stage as specified by laboratory guidelines ( see
www. ncagr. com/ agronomi/ ptaflyer. htm or contact your
county Extension center).
North and South Carolina have numerous sources
of plant and animal manures and by- products. This
region also has a favorable climate for growing a diver-sity
of rotational and green manure cover crops that can
provide needed nitrogen and other nutrients. Farmers
should study their crops to fully understand production
requirements, nutrient needs, and common production
problems. Crops differ in their nutrient removal rates
( Table 6- 1), and nutrient sources differ in their nutrient
contents ( Table 6- 2).
Certain inputs are allowable on organic farming
systems, if applied according to guidelines. These in-clude
mostly natural and a few synthetic materials. The
National List of Allowed and Prohibited Substances
under the National Organic Program is available
online: http:// www. ams. usda. gov/ nop/ NationalList/
FinalRule. html. This list specifies synthetic substances
allowed for use and nonsynthetic substances prohibited
for use in crop production. The Organic Materials Re-view
Institute ( OMRI) was developed to review mate-rials
for approval in order to simplify the National List.
OMRI classifies materials as either allowed ( A) or
regulated ( R), and lists generic and brand names of
materials. OMRI can be accessed via the Web at
www. omri. org; or by mail or phone at Box 11558,
North Carolina Organic Grain Production Guide 23
Table 6- 1. Nutrient removal ( in pounds) by different crops. Missing values
indicate no data available.
Corn Sorghum- Irish Tobacco
Nutrient grain Soybean Fescue Ryegrass Sudan Potato ( flue- cured)
N 112 188 135 215 319 90 85
P 2 O 5 53 41 65 85 122 48 15
K 2 O 40 74 185 240 467 158 155
S 10 23 20 - - 7 12
Ca 2 10 - - - 5 75
Mg 8 10 13 40 47 7 15
B 0.03 - - - - - -
Cu 0.06 0.05 - - - - 0.03
Zn 0.15 0.05 - - - 0.08 0.07
Yield 150 bu 50 bu 3.5 tons 5 tons 8 tons 15 tons 3,000 lbs
Table 6- 2. Nutrient content of selected natural sources. These are general values and may not accurately repre-sent
the content of any specific source. Laboratory analysis should be performed prior to utilizing these materi-als.
Missing values indicate no data. Use of any specific source should be approved by the certifying authority
prior to submitting an application for organic certification.
Source Units N a P 2 O 5 K 2 O S Ca Mg B Cu Mn Zn
Swine lagoon lb/ acre 109b 37.1c 93.1c 10 26 8.3 0.18 0.3 0.34 1.5
liquid in/ acre 68c
Broiler, fresh
manure lb/ ton 15.6 17 11 2 10 4 - - - -
Broiler,
stockpiled litter lb/ ton 21.6 80 34 12 54 8 0.04 0.27 0.59 0.55
Turkey,
fresh manure lb/ ton 16.2 25 12 - 27 2 - - - -
Turkey,
stockpiled litter lb/ ton 21.6 72 33 9.5 42 6.8 0.05 0.34 0.62 0.56
Blood, dried lb/ ton 240 to 60 - - 6 - - - -
300 ( total N)
Bone meal, raw lb/ ton 70 ( total N) 440 - 4 440 12 - - - -
Shrimp process
waste lb/ ton 58 ( total N) 200 - - - - - - - -
Cotton motes lb/ ton 40 ( total N) 10 60 12 80 14 - - - -
Peanut hull meal lb/ ton 24 ( total N) 12 16 - - - - - - -
Wood ash lb/ ton 0.0 40 120 - 400 20 - - - -
a Plant- available N unless otherwise stated.
b Plant- available N values shown represent estimate for material incorporated into the soil unless specified otherwise.
c Sprinkle- irrigated and not incorporated.
Eugene, OR 97440, ( 541) 343- 7600. Other materials
should be considered prohibited until further notice. In
all cases, input use should be included in the farm plan
and confirmed by the certifying authority prior to sub-mitting
an application for certification as an organic
farm.
Critical aspects of soil fertility management in-clude
pH, major nutrients ( nitrogen, phosphorus, potas-sium),
secondary nutrients ( sulfur, calcium, magne-sium),
and micronutrients ( especially boron, copper,
manganese, and zinc; but also iron, molybdenum, chlo-rine,
selenium, and cobalt). A summary of soil fertility
24 North Carolina Organic Grain Production Guide
1 Inputs are limited to materials approved on the National Organic Program List or on the OMRI- approved source list after consultation with the certifying agent regarding need to docu-ment
deficiency and application records.
2 Avoid over- application of micronutrients since toxicities can occur.
3 See restrictions in text.
4 Documentation of nutrient deficiency required.
5 Deficiencies of Co, Mo, and Se are not common in North Carolina, and these elements are not included in routine tissue analysis performed by the NCDA& CS. Consult a Cooperative
Extension office for information regarding private agricultural laboratories.
Cobalt ( Co), Iron ( Fe), Molybdenum ( Mo),
Selenium ( Se)
Manures, animal and plant by- products, sulfates, car-bonates,
oxides, or silicates4
Chlorides, nitrates
Table 6- 3. Soil fertility management options.
Problem
Effect on Plants Documentation Supply Options1 Not Allowed
Secondary Nutrients
Magnesium ( Mg)
Boron ( B)
Copper ( Cu)
Hydrated or burnt lime
[ Ca( OH) 2 , CaO]
Synthetic fertilizers
Lime ( standard, ground calcitic or dolomitic carbonate
source)
Dolomitic lime, Epsom salts ( MgSO 4 ) 4, sulfate of potash
magnesium, bone meal, plant by- products ( cottonseed
meal, wood ash)
Manures, animal and plant by- products,
soluble boron fertilizers4
Manures, animal and plant by- products,
sulfates & oxides4
Soil test
Soil test, tissue
analysis
Tissue analysis
Soil test, tissue
analysis
Nutrient solubility,
root development,
microbial activity
Component of chlorophyll, cell
pH and cation balance, en-zyme
activation
Cell wall & membrane stabili-zation,
cell growth, carbohy-drate
& protein metabolism,
pollen germination
Enzyme component, photosyn-thesis,
respiration, cell wall
lignification, pollen formation
pH
Sulfur ( S) Synthetic fertilizers
Tissue analysis
Component of proteins; volatile
compounds of mustard, garlic,
onion
Calcium ( Ca) Ca( OH) 2 , CaO, calcium
nitrate [ Ca( NO 3 ) 2 ]
Lime ( mined carbonates), gypsum ( CaSO 4 ), bone
meal, ash
Soil test, tissue
analysis
Cell wall & membrane stabiliza-tion,
cell growth, osmoregulation
Manures3, plant by- products ( cotton motes, peanut meal),
elemental sulfur4, gypsum ( CaSO 4 ), Epsom salt ( MgSO 4 ) 4,
sulfate of potash ( K 2 SO 4 ) 4
Chlorides
Manganese ( Mn) Soil test, tissue
analysis
Manures, animal and plant by- products, sulfates &
oxides4
Chlorides
Zinc ( Zn)
Enzyme activation, protein
component, photosynthesis,
cell growth
Enzyme component & activa-tion,
protein synthesis
Soil test, tissue
analysis
Manures, animal and plant by- products,
sulfates & oxides4
Chlorides
Tissue analysis5
Major Nutrients
Nitrogen ( N) Synthetic fertilizers, sew-age
sludges, municipal
waste composts
N fixation by legumes, manures3, animal by- products
( blood, fish), plant by- products such as cotton ( re-stricted
due to pesticide use) or apple fermentation
wastes, mined sodium nitrate ( NaNO 3 ) 3
Component of proteins, Tissue analysis
chlorophyll
Phosphorus ( P) Processed rock phos-phates
Manures3, rock phosphate, animal by- products ( bone meal;
fish, shrimp, & oyster scraps; leather)
Soil test, tissue
analysis
Component of nucleic
acids
Potassium ( K) Manures3, plant by- products ( ash, dried seaweed), green- KCl if excess chloride
sand, sulfate of potash ( K 2 SO 4 ) 4, possibly muriate of potash
( KCl) 3,4
Soil test, tissue
analysis
Water, salt, & pH balance;
enzyme activation; protein
synthesis; photosynthesis
Micronutrients2
North Carolina Organic Grain Production Guide 25
parameters and organic management options is given in
Table 6- 3.
Soil pH is important because it influences nutri-ent
solubility, microbial activity, and root growth.
The low pH levels common in native Carolina soils
continue to be the most common limiting factor for
plant development seen in samples submitted to the
NCDA& CS Agronomic Division Laboratory. Since
most agricultural lime is from naturally- occurring
minerals of relatively low solubility, its use is gener-ally
allowed in organic farming systems. Hydrated
limes and burnt limes are not allowed. Pelletizing
agents should be evaluated to determine that they
are not prohibited materials.
Nitrogen ( N) is the most frequently limiting nutri-ent
for crop production. Organic farms need to supply
N through sources such as legumes, animal wastes or
by- products, plant- processing by- products, or limited
additions of mined mineral deposits. It is possible for a
nitrogen- fixing legume or legume- and- grass mixture
cover crop to provide adequate nitrogen for certain
cash crops. A seed inoculum is recommended for le-gumes
unless adequate native inoculum is present, and
adequate soil fertility is needed to ensure no other fac-tors
limit legume growth. Inoculums, however, must
not be genetically engineered. Nitrogen- fixing cover
crops for summer in North Carolina include cowpeas
and soybeans. Winter N- fixing cover crops include
hairy vetch, Cahaba vetch, Austrian winter peas, and
many clovers. Many farmers in North Carolina use
composted or uncomposted poultry litter to supply the
nitrogen needs for their organic field crops. Poultry
litter and poultry by- products are available in many
parts of the state. Mined nitrates, such as sodium nitrate
( NaNO 3 , bulldog soda, or Chilean nitrate) may be used,
but are limited to a maximum of 20 percent of the
crop’s total N requirement. Constantly relying upon
NaNO 3 , a restricted substance in organic agriculture,
will be questioned by a certification agency.
Other nutrients. Phosphorus, potassium, calcium,
magnesium, sulfur, copper, manganese, and zinc can
generally be supplied in adequate amounts through
additions of lime ( calcium, magnesium), animal or
plant by- products or wastes ( phosphorus, potassium,
sulfur, micronutrients), or permissible mineral inputs.
Naturally occurring minerals of relatively low solubil-ity
are generally allowed ( lime, gypsum, rock phos-phate,
rock dusts, mined humates).
In addition, the following naturally occurring
minerals of relatively high solubility may be applied
if used in compliance with the National List:
• Magnesium sulfate ( Epsom salt), with a docu-mented
soil deficiency.
• Sulfate of potash and potassium magnesium
sulfate, if from an approved source and with a
documented soil deficiency.
• Muriate of potash, if derived from a mined
source and applied in a manner that mini-mizes
chloride accumulation in the soil. This
may be acceptable for most crops in the Caro-linas
with a soil test to document the defi-ciency
and recommend an application rate.
• Many micronutrient salts, with documented
soil deficiency and if not in the form of nitrate
or chloride salts. This includes various soluble
boron products and sulfates, carbonates, ox-ides,
or silicates of zinc, copper, iron, molyb-denum,
selenium, and cobalt.
Numerous animal and plant by- products are
available to provide essential crop nutrients ( Table 6-
2). It is important to check with the certifying
agency before using any input.
Tillage Practices
Management of soil tilth, organic matter, and fertility is
an important aspect of a successful organic farming
system. Current organic systems usually require tillage
prior to planting and cultivation after planting, espe-cially
for corn and soybean production, to control
weeds and reduce the incidence of seedling diseases
and insect pests. However, tillage destroys the organic
matter that is critical in improving soil fertility and soil
water- holding capacity. The use of rotations with cover
crops where the soil surface is covered with a growing
crop for most of the year is important in maintaining
organic matter content during periods when corn is not
grown. Tillage should be performed when soil moisture
26 North Carolina Organic Grain Production Guide
is low enough to prevent compaction. Since primary
tillage operations are usually performed at least a
month before a crop is planted, this requires careful
planning and the ability to take advantage of periods of
dry weather. No- till agriculture in organic systems is
starting to be used in parts of the country. The Rodale
Institute has experimented with no- till organic using
cover crops and tractor- mounted rollers to kill the
cover just before planting into it.
Documenting Crop Nutrient Deficiencies
and Soil Quality Maintenance
Since use of some soil amendments is limited to cases
of nutrient deficiency, organic producers should main-tain
records of soil test results and plant tissue analysis
to document specific nutrient deficiencies that need
correction. Soil test records can also be useful in docu-menting
soil quality maintenance because they will
show changes in humic matter and nutrient levels over
time. It is important to avoid topsoil erosion from
excessive cultivation for weed control ( declines in
humic matter indicate erosion losses) and to avoid
accumulation of excess phosphorus and micronutrients
following application of manures and composts.
Composts and Manures
Specific guidelines must be followed when applying
composts and manures in organic farming systems.
Materials must be applied at agronomic rates in com-pliance
with any applicable nutrient management
guidelines and in ways that avoid excess nutrients ( see
http:// www. soil. ncsu. edu/ nmp/ ncnmwg/ or contact
your local Soil and Water Conservation District office).
Raw animal manures must be
• composted according to specific criteria,
• applied to land used for a crop not intended for
human consumption,
• incorporated into the soil at least 90 days prior to
the harvest of an edible ( human- consumed)
product not contacting soil or soil particles, or
• incorporated into the soil at least 120 days prior to
the harvest of an edible product that does con-tact
soil or soil particles.
The guidelines for compost production for organic
agriculture state that the initial C: N ratio must be be-tween
25: 1 and 40: 1, and a temperature between 131 º
and 170 º F must be achieved. This temperature must be
maintained for at least 3 days for in- vessel or static-aerated
pile systems or for at least 15 days during
which there are at least five turnings for windrow sys-tems.
Composts not meeting these criteria must be
applied based on other raw manure criteria, which also
apply to lagoon liquids, lagoon solids, and stockpiled
poultry litter. Ashes of manures may not be used, but
ashes from other untreated plant and animal materials
may be applied if not combined with any prohibited
substances.
Avoid over- reliance on animal manures, since this
could lead to accumulation of excess phosphorus, cop-per,
and zinc in soils. For example, based on the gen-eral
nutrient contents shown in Tables 6- 1 and 6- 2,
stockpiled turkey litter, applied at a rate of 5 tons per
acre, would supply approximately the amount of N
removed by a 150 bushel per acre corn crop. Note that
the amount of phosphorus added ( as P 2 O 5 equivalent)
would be 360 pounds per acre, while crop removal
would only be 53 pounds per acre. Similarly, 2.8
pounds per acre of zinc would be added, while crop
removal would only be 0.15 pounds per acre. Sporadic
use of manures in conjunction with more frequent use
of legume cover crops, green manures, or other N
sources is an excellent way to supply plant nutrients in
appropriate amounts.
NC State University Soilfacts bulletins describe
specific types of manures ( such as swine, poultry,
and dairy) at http:// www. soil. ncsu. edu/ about/ publi-cations/
index. php). Since nutrient composition of
animal manures and composts can vary widely, it is
wise to submit a sample to the Plant and Waste
Analysis Laboratory of the NCDA& CS Agronomic
Division before use. Sewage sludge and composted
municipal wastes are not allowed on organic fields.
North Carolina Organic Grain Production Guide 27
Chapter 7. Weed Management
Mike Burton, Assistant Professor, Crop Science, NC State University
Randy Weisz, Crop Science Extension Specialist, NC State University
Alan York, Crop Science Extension Specialist, NC State University
Molly Hamilton, Crop Science Extension Assistant, NC State University
Weed pest management must be an ongoing consid-eration
for organic farmers to achieve acceptable
yields and crop quality. A system of weed manage-ment
that includes multiple tactics will help reduce
losses in both the short and long term. Various weed
management tactics fall into two major categories:
cultural and mechanical. Cultural tactics are associ-ated
with enhancing crop growth or cover, while
mechanical tactics are used to kill, injure, or bury
weeds. During a cropping season, successful organic
weed management will rely on the cultural tactics
described below to achieve competitive crop plants
and will use the mechanical tactics to reduce the
weed population that emerges in the crop. When a
cash crop is not in the field, plant a cover crop or use
an occasional shallow tillage to kill germinating and
emerging weeds.
Cultural Tactics
Crop rotation
It is beneficial to have a rotation system that includes
crops with different life cycles, growth patterns, and
management techniques. This will reduce the chance
that weeds can proliferate over successive years. For
example, a rotation could include a summer crop,
winter crop, legume, grass, a cultivated crop ( corn)
and a noncultivated crop ( wheat or hay). Because
some weeds are triggered to germinate by tillage,
rotations of tilled and no- till crops ( such as a forage
or hay crop) may also be of benefit.
Cultivar and cover crop selection
Competitive differences exist among crop cultivars.
Tall cultivars and cultivars with rapid establishment
and quick canopy closure are reportedly more competi-tive
with weeds than short or dwarf cultivars or culti-vars
( or seedlots) that
have low seed vigor, are
slow growing, or are less
bushy. Some weed spe-cies
are suppressed by
crop- produced allelo-chemicals
( naturally produced compounds that can
inhibit the growth of other plants) in standing crops or
in residues of allelopathic crops ( for example, a rye
cover crop). Results of studies conducted with wheat
and rye have demonstrated that the production of
allelochemicals varies widely with cultivar and can
change in concentration during crop development.
Allelopathic characteristics of cultivars are being inves-tigated
in the small grains breeding programs at several
universities.
Seed quality
Seed cleanliness, percent germination, and vigor are
characteristics that can influence the competitive
ability of the seedlings. Seed that has not been care-fully
screened ( especially farmer- saved seed) is often
of lower quality than certified seed and may contain
unknown quantities of weed seed or disease. Plant-ing
this seed may result in the introduction of pests
not previously observed on the farm. There is also a
risk that weed density will increase and that weeds will
be introduced to previously uninfested parts of the
field. Germination rate and vigor are equally important
to weed management because they collectively affect
stand quality and time to canopy closure.
Planting – sowing date, seeding rate, row spacing,
and population.
Sowing date and seeding rate affect the final crop
population, which must be optimum to compete with
weeds. Carefully maintained and adjusted planting
Top. Row cultivator shovel.
Below. Flex- tine weeder.
28 North Carolina Organic Grain Production Guide
equipment will ensure that the crop seed is uniformly
planted at the correct depth for optimum emergence.
Narrower rows and a slightly increased plant popula-tion
( up to 10 percent higher than usual) will also
help the crop compete with weeds.
Cover crops
Cover crops can provide benefits of reduced soil ero-sion,
increased soil nitrogen, and weed suppression
through allelopathy, light interception, and the physical
barrier of plant residues. Cover crops such as rye, triti-cale,
soybean, cowpea, or clover can be tilled in as a
green manure, allowed to winter kill, or be killed or
suppressed by undercutting with cultivator sweeps,
mowing, or rolling. Warm- season cover crops help to
suppress weeds by establishing quickly and out- com-peting
weeds for resources. It is important to manage
cover crops carefully so that they do not set seed in the
field and become weed problems themselves.
Fertility— compost and manures
Uncomposted or poorly composted materials and
manures can be a major avenue for the introduction
of weed seeds. However, soil fertility that promotes
early and sustained crop growth helps to reduce the
chance that weeds will establish a foothold. Areas of
poor productivity leave the door open to diseases,
insect pests, and weeds.
Sanitation and field selection
Weeds are often spread from field to field on tillage,
cultivation, or mowing equipment. Cleaning equip-ment
before moving from one field to another or
even after going through a particularly weedy sec-tion
can prevent weeds from spreading between
fields or within fields. A short investment of time to
clean equipment can pay large dividends if it pre-vents
spread of problem weeds. When transitioning
to organic systems, it is highly advisable to start with
fields that are known to have low weed infestations.
Fields with problem weeds, such as Italian ryegrass,
wild garlic, Johnsongrass, or bermudagrass, should
be avoided if possible, as these weed species will be
difficult to manage.
Mechanical Tactics
A healthy, vigorous crop is one of the best means of
suppressing weeds. However, some physical tactics
are almost always needed to provide additional
weed control. The methods discribed below can be
used together with good cultural practices to kill or
suppress weeds – leaving the advantage to the crop.
The goals of mechanical weed control are to elimi-nate
the bulk of the weed population before it com-petes
with the crop and to reduce the weed seed
bank in the field. Important factors to consider for
mechanical weed control are weed species present
and their size, soil condition, available equipment,
crop species and size, and weather. Since it might
not be necessary to use a tactic on the entire field,
knowledge of weed distribution and severity can be
valuable. Tillage, blind cultivation ( shallow tillage
of the entire field after planting), and between- row
cultivation are important aspects of mechanical
weed control.
Tillage
Proper field tillage is important to creating a good
seedbed for uniform crop establishment, which is a
critical part of a crop’s ability to compete with
weeds. Tillage should also kill weeds that have al-ready
emerged. In the spring when the soil is warm,
weed seeds often germinate in a flush after tillage. A
moldboard plow will bury the weed seeds on or near
the surface ( those that come out of dormancy as the
soil warms) and bring up dormant weed seeds from
deeper in the soil. These weed seeds will normally
be slower to come out of dormancy than weed seeds
previously near the surface. Chisel plowing or
disking does not invert the soil and can result in an
early flush of weeds that will compete with the crop.
If there is enough time before planting, the stale
seedbed technique can be used as an alternate ap-proach.
In this technique, soil is tilled early ( a seed-bed
is prepared), which encourages weed flushes,
and then shallow tillage, flaming, or an organically
approved herbicide is used to kill the emerged or
North Carolina Organic Grain Production Guide 29
emerging weed seedlings. While this technique
should not be used in erosion- prone soils, it can be
used to eliminate the first flush or flushes of weeds
that would compete with the crop.
Blind cultivation
Blind cultivation is the shallow tillage of the entire
field after the crop has been seeded. Generally, it is
used without regard for the row positions. It pro-vides
the best opportunity to destroy weeds that
would otherwise be growing within the rows and
that are not likely to be removed by subsequent me-chanical
tactics. Blind cultivation stirs soil above the
level of seed placement ( further emphasizing the
need for accurate placement of the crop seed), caus-ing
the desiccation and death of tiny germinating
weed seedlings. Crop seeds germinating below the
level of cultivation should not be injured. The first
blind cultivation pass is usually performed immedi-ately
before the crop emerges, and a second pass is
performed about a week later. This depends, of
course, on weather, soil and crop conditions, and
weed pressure. Blind cultivation is most effective
when the soil is fairly dry and the weather is warm
and sunny to allow for effective weed desiccation.
Blind cultivation equipment includes rotary hoes,
tine weeders, spike tooth harrows, springtooth har-rows,
and chain link harrows.
Between- row cultivation
Between- row cultivation should not be the pri-mary
mechanical weed control tactic, but should
be used as a follow- up tactic to control weeds that
escaped previous efforts. Between- row cultivation
should be implemented when weeds are about 1-
inch tall and the crop is large enough not to be
covered by soil thrown up during the cultivation
pass. Usually, more than one cultivation pass is
needed. It may be useful to reverse the direction
of the second cultivation pass in order to increase
the possibility of removing weeds that were
missed by the first cultivation. Planting corn in
furrows can allow more soil to be moved on top
of weeds and may be a useful practice on some
farms. All cultivation passes should be done be-fore
the canopy closes or shades the area between
the rows. After this time, the need for cultivation
should decrease, as shading from the crop canopy
will reduce weed seed germination and equipment
operations can severely damage crop plants. Cul-tivation
works best when the ground is fairly dry
and the soil is in good physical condition.
There are many types of cultivator teeth, shanks, and
points. Choose the cultivating equipment that works
best in your soils. Points for cultivator teeth vary in
type and width. Half sweeps ( next to the row) and
full sweeps ( between rows) are probably the most
versatile and common, but each type of point works
best under certain conditions and on certain weed
species. Using fenders on cultivators at the first pass
can keep the soil from covering up the crop. Cultiva-tor
adjustments are very important and should be
made to fit the field conditions. Tractor speed should
also be modified through the field to compensate for
variability in soil type and moisture.
Other methods of mechanical weed control may
be effective and efficient depending on the available
equipment, budget, and goals of the farm.
Flame weeding
Flame weeding provides fairly effective weed con-trol
on many newly emerged broadleaf species and
can be used in tilled or no- till fields. Grasses may
not be well controlled by flaming because their
growing points are often below the soil surface.
Flame weeding should only be performed when field
moisture levels are high and when the crop is small.
Hand weeding and topping
Walking fields and hand weeding or topping ( cutting
off the weed tops) can vastly increase familiarity with
the condition of the crop and distribution of weeds or
other pests. Farmers who are familiar with problem
locations can remove patches of prolific weeds before
they produce viable seeds and reduce long- term prob-lems
caused by weeds that escaped management. Top-ping
of flowering weeds can reduce seed set and the
weed seed bank in the field.
30 North Carolina Organic Grain Production Guide
Herbicides
Several herbicides have been approved for certified
organic farming. These include acetic acid ( distilled
vinegar), clove oil, nondetergent soap- based pesticides,
some corn gluten meal products, and boiling water.
While these products have potential for controlling
weeds in organic farming systems, no research has
been conducted with them in grain crops in North
Carolina. Therefore, we cannot give recommendations
for their use in this state. The cost of herbicides ap-proved
for organic farming may also be prohibitively
expensive for field crops. The Organic Materials Re-view
Institute ( OMRI) publishes a list of commercially
available products that can be used in certified organic
operations for weed control ( www. OMRI. org). Condi-tions
for use of an approved herbicide must be docu-mented
in the organic system plan as specified in the
2000 National Organic Plan.
No- till Organic Weed Control
Recent research on no- till organic agriculture shows
some potential for organic systems to be much less
reliant upon mechanical weed control. The basic
premise for no- till organic weed control is to plant a
cover crop with high residue, mow or roll that cover
crop, and no- till plant into the residue. This system,
however, takes a lot of planning to work well. For
more information on organic no- till farming, contact
the Rodale Institute by mail at 611 Siegfriedale
Road, Kutztown, PA 19530- 9320, by telephone at
610- 683- 1400, or on the Web: http://
www. rodaleinstitute. org.
Weed Guides
Several weed identification guides are available for purchase through various publishers. NC State
University offers Identifying Seedling and Mature Weeds, an excellent and inexpensive resource
developed for the southeastern United States. It does not, however, include some weed species that are
troublesome in North Carolina grain crop production. Another recommended guide is Weeds of the
Northeast. A few guides are also available on the Web:
http:// www. ppws. vt. edu/ weedindex. htm
http:// web. aces. uiuc. edu/ weedid/
http:// www. weeds. iastate. edu/ weednews/ ncseed. htm
Ordering information
Identifying Seedling and Mature Weeds ( AG- 208). Stuckey, Monaco and Worsham. ( 1989).
Communication Services, Box 7603, NC State University, Raleigh, NC 27695- 7603. Telephone: 919-
513- 3045. $ 10.
Weeds of the Northeast. Uva, Neal and DiTomaso ( 1997). Cornell University Press,
P. O. Box 6525, Ithaca, NY 14851- 6525. Telephone: 607- 277- 2211
North Carolina Organic Grain Production Guide 31
Chapter 8. Organic Certification
Jim Riddle, Organic Policy Specialist, Rodale Institute’s The New Farm ®
Myron Fountain, former Executive Director, North Carolina Crop Improvement Association
Tony Kleese, Executive Director, Carolina Farm Stewardship Association
In order to sell, label, or represent their products
as “ organic,” growers who sell $ 5,000 ( or more) a
year of organic products must be certified by a
USDA- accredited certifying agent. The National
Organic Program Final Rule ( NOPFR) spells out
requirements for organic crop and livestock pro-duction,
handling, certification, and record- keep-ing.
The NOPFR, and other related documents,
can be viewed on the Web at www. ams. usda. gov/
nop/. ( See Table 8.1.)
Who Must Be Certified?
If an operation earns $ 5,000 ( or more) in a year
from organic agricultural products, that operation
must be certified. Operations selling less than
$ 5,000 a year in organic agricultural products and
direct marketing the products to the end- user are
exempt from certification, but they must operate in
compliance with the federal regulations and may not
label products as certified organic.
Organic Certification Process
Because all certifiers must follow USDA require-ments,
the organic certification process is similar
across certifiers. First, farms must comply with the
federal standards for organic production ( Table 8- 1).
The next steps involve choosing a certifier and com-pleting
an Organic Farm ( or System) Plan. The Or-ganic
Farm Plan is also considered the application
for certification. The certifying agent may ask ques-tions
to assess the applicant’s eligibility. The Or-ganic
Farm Plan Questionnaire must be completed,
including farm maps and a three- year field history
for crops planted and inputs applied. The completed
Organic Farm Plan ( the application), licensing agree-ment,
and fees should then be submitted to the certi-fication
agency.
The certifying agent then reviews the Organic
Farm Plan and accompanying documentation to en-sure
completeness and determine whether the appli-cant
appears to comply or has the ability to comply.
The certifying agent also verifies information regard-ing
any previous certifications, notification of non-compliance,
or denials of certification.
The next step of the process is an on- site inspec-tion
of the farm. The certifying agent assigns an
organic inspector who calls the applicant to set up an
appointment. The inspection may take 3 to 6 hours,
depending on the complexity of the operation. In-spectors
need to verify information from the Organic
Farm Plan. They inspect fields, farm buildings and
equipment, assess contamination risks, fill out an on-site
inspection report, and gather as much informa-tion
as needed to determine if the operation is in
compliance. Inspectors evaluate crop health and
growth, soil tilth, the fertility management program,
pest and weed management strategies, and the
applicant’s understanding and commitment to compli-ance.
They also review records to ensure monitoring
and compliance. The inspector may be authorized to
take soil, tissue, or product samples for analysis. The
inspector reviews identified noncompliance issues at
the time of the inspection. The inspector conducts an
exit interview to confirm the accuracy and complete-ness
of the observations and information gathered,
addresses the need for additional information, and dis-cusses
issues of concern. The inspector also completes
a report based on the information gathered. The inspec-tor
does not make the certification decision, but identi-fies
noncompliance issues with regard to organic
standards. The inspection report and all associated
paperwork are sent to the certifying agent.
32 North Carolina Organic Grain Production Guide
Table 8- 1. Organic certification federal standards
To become a certified organic production operation, the farm and farm practices must comply with the Organic
Foods Production Act of 1990 and the USDA National Organic Program rules and regulations ( Federal Register, Vol.
65, No. 246, pgs. 80367- 80663).
In simplified terms, National Organic Standards for crop farms require
• three years ( 36 months prior to harvest) with no application of prohibited materials ( no synthetic fertilizers, pesti-cides,
or GMOs) prior to certification;
• distinct, defined boundaries for the operation;
• implementation of an Organic System Plan, with proactive fertility systems; conservation measures; and environ-mentally
sound manure, weed, disease, and pest management practices;
• monitoring of the operation’s management practices;
• use of natural inputs and/ or approved synthetic substances on the National List, provided that proactive manage-ment
practices are implemented prior to use of approved inputs;
• use of organic seeds, when commercially available ( no use of seeds treated with prohibited synthetic materials
such as fungicides); and
• use of organic seedlings for annual crops ( see text discussion).
National Organic Standards prohibit
• use of genetically engineered organisms, ( GMOs) defined in the rule as “ excluded methods”;
• residues of prohibited substances exceeding 5 percent of the EPA tolerance ( certifier may require residue analysis
if there is reason to believe that a crop has come in contact with prohibited substances or was produced using
GMOs);
• sewage sludge or irradiation;
• raw manure and compost ( see text discussion);
• any other prohibited substances on the National List; and
• field burning to dispose of crop residues ( may only burn to suppress disease or stimulate seed germination – flame
weeding is allowed).
In addition, organic operations must
• maintain or improve the physical, chemical, and biological condition of the soil, minimize soil erosion, and imple-ment
soil- building crop rotations;
• use fertility management systems that do not contaminate crops, soil, or water with plant nutrients, pathogens,
heavy metals, or prohibited substances;
• maintain buffer zones, depending on risk of contamination;
• prevent commingling on split operations ( the entire farm does not have to be converted to organic production,
provided that sufficient measures are in place to segregate organic from nonorganic crops and production in-puts);
and
• maintain records.
North Carolina Organic Grain Production Guide 33
A certification committee, staff member, or re-view
committee reviews the Organic Farm Plan, the
inspection report, and all associated documentation.
If the certifying agent determines compliance in all
procedures and activities, the applicant is granted
certification and is issued a certificate of organic
operation. If the certifying agent determines any
minor noncompliances, the applicant has the oppor-tunity
to correct these noncompliances as a condition
of certification.
To continue organic certification each year, the
certified farmer must pay annual certification fees,
submit an updated Organic Farm Plan detailing
changes from the previous year, and submit an up-date
on correction of minor noncompliances previ-ously
identified by the certifying agent. Other
records or information may be needed if deemed
necessary. Each farm must be inspected at least once
annually to maintain certification. The updated Or-ganic
Farm Plan and inspection report must also be
completely reviewed by the certifying agent to re-ceive
an updated certificate for the organic opera-tion.
Denial of Certification
If certification is to be denied, the certifying
agent must provide an applicant with written notifi-cation
of noncompliance, giving the date by which
the correction must be accomplished, and specifying
any documentation necessary to support correction.
The applicant may rebut in writing any noncom-pliances
identified by the certifying agent. When a
correction is not possible, a notification of noncom-pliance
and notification of denial of certification is
provided to the applicant. This notification is also
provided to the USDA National Organic Program
Administrator. The applicant may re- apply for certi-fication
or request mediation with the certifying
agent. The applicant may file an appeal of the denial
of certification to the USDA National Organic Pro-gram
Administrator. If the certifying agent has rea-son
to believe that the applicant has made false state-ments
or otherwise misrepresented compliance, the
certifying agent may also deny certification simulta-neously
with issuance of notification of noncompli-ance.
Record- keeping Requirements for
Certified Operations
Record- keeping is very important to organic certifi-cation.
A certified operation must maintain records
concerning the production, harvest, and handling of
agricultural products that are intended to be sold,
labeled, or represented as organic. The records must
be adapted to the particular business that the certified
operation is conducting. For example, an organic
grain production farm must keep records pertaining
to the particular operations that deal with the produc-tion,
handling, and marketing of the organic grain
crops, such as storage, clean- out, and transportation
records. The records must also fully disclose all ac-tivities
and transactions of the certified operation in
sufficient detail as to be readily understood and au-dited.
Records must be maintained for at least five
years beyond their creation and be sufficient to dem-onstrate
compliance with the National Organic Plan
rules and regulations. The certified operation must
make all relevant records available for inspection
and copying during normal business hours by autho-rized
representatives of the Secretary of Agriculture,
the applicable state program’s governing official,
and the certifying agent.
Certification Agencies
A list of all USDA- accredited organic certifying
agencies can be found on the Web at
www. ams. usda. gov/ nop/ CertifyingAgents/
Accredited. html or by request through the National
Organic Plan ( NOP) office at 1400 Independence
Avenue, SW, Room 2510 South Building, Washing-ton,
DC, 20250.
34 North Carolina Organic Grain Production Guide
Choosing a Certifier
When choosing an organic certifier, an applicant
should consider several factors. First, it may be
helpful to choose a certifier that the end- user of
your product recommends or recognizes. The lo-cation
of inspectors that the certifier uses should
also be considered, as most certifiers require the
applicant to pay all expenses associated with the
on- site inspection, including travel. Since the
USDA requires that certifiers fully disclose all
fees, an applicant can compare certifiers based on
expense or fees. Also consider the turn- around
time required by certifiers to obtain certification,
and the experience the certifier has in certifying a
particular type of operation. Some applicants
choose their certifier based on the agency’s level
of involvement in organic certification policy and
advocacy at state and national levels.
Specific Requirements
and Suggestions for Organic
Compliance in Grain Production
Isolation buffers
The size of isolation buffers between organic land
and adjacent nonorganic land depends on land uses,
prevailing winds, runoff directions, ditches, and
other barriers. It is usually between 20 and 50 feet.
However, cross- pollinated or wind- pollinated or-ganic
crops ( such as corn), should be isolated from
nonorganic crops of the same type by 660 feet to
maintain seed purity. If an applicant can verify with
a written statement from his or her neighbors that no
prohibited materials are being used on adjoining
land, then the applicant may not need a buffer at all.
Organic seed
Organic seed must be used when commercially
available. However, in many cases, the crop or vari-ety
desired is not commercially available as organic
seed. Generally, the applicant must contact at least
three seed companies or sources that carry organic
seeds in an effort to obtain organic seed of the crop
or variety desired. The three seed sources contacted
must produce or supply seed of the crop kind de-sired.
The applicant must also document the contact
( including the date; whether the contact involved a
telephone, fax, letter, or email message; the crop and
variety; and the most comparable variety with or-ganic
seed source and price). A copy of this docu-mentation
may be required by the organic certifier if
seed is used that is not organic. Excellent resources
for availability of organic seed for crop production
can be found by contacting these organizations:
• http:// attra. ncat. org/ attra- pub/ altseed. html
National Sustainable Agriculture Information
Service, 1- 800- 346- 9140
P. O. Box 3657, Fayetteville, AR 72702
• http:// www. savingourseed. org/
Save Our Seed, 540- 894- 8866
286 Dixie Hollow, Louisa, VA 23093
• http:// www. omri. org/ OMRI_ SEED_ list. html
Organic Materials Review Institute, 541- 343-
7600. Box 11558, Eugene, OR 97440
Split ( nonorganic and organic) production
A split operation may require additional record- keep-ing
and detailed auditing. The dates of use, cleaning,
and purging of equipment ( including field prepara-tion,
cultivation, harvesting, and handling equip-ment)
used in both nonorganic and organic opera-tions
must be recorded.
Accidental contamination
Accidental contamination of a farm by prohibited
substances can be a result of spraying by the Depart-ment
of Transportation ( DOT), electrical companies,
or neighbors. It is important to communicate very
clearly about your organic operation and display
signs that indicate organic land. The DOT and elec-trical
companies should be informed of the location
of organic land and be specifically asked to avoid
spraying the area.
North Carolina Organic Grain Production Guide 35
Storage and product transportation
Organic and nonorganic grain ( or field crops) must
not commingle. Storage bins or containers and areas
used for organic grains should be thoroughly cleaned
before use and clearly labeled “ organic.” Documen-tation
of the cleaning of transportation vehicles will
be required. The date, previous product transported,
organic product transported, cleaning activity, and
name( s) of the driver( s) are generally needed for the
documentation. Consult the certifier about specific
cleanout procedures.
Pesticides
A number of pesticides— mainly nonsynthetic compounds and biocontrols— are approved for
use in certified organic production systems. Insecticides include neem, Bacillus thuringiensis,
Beauvaria spp., diatomaceous earth, pyrethrum, spinosads, horticultural oils, and species of Tricho-derma.
Fungicides include hydrogen peroxide, potassium and sodium bicarbonate, copper products,
sulfur, species of Pseudomonas, and pesticidal soaps. While these products have potential for con-trolling
insect or disease pests, or both, no research has been conducted with them in grain crops in
North Carolina, and we cannot make recommendations for their use in this state. The cost of pesti-cides
approved for organic production may also be prohibitively expensive for field crops. Condi-tions
for use of an approved pesticide must be documented in the organic system plan as required by
the 2000 National Organic Plan.
The Organic Materials Review Institute ( OMRI) publishes a list of commercially available
products that can be used in certified organic operations for pest control: www. OMRI. org.
36 North Carolina Organic Grain Production Guide
However, there are markets in North Carolina for
food- grade organic wheat.
Marketing Plan
It is always a good idea to have a marketing plan,
especially when marketing organic grains. Research
for a market is a key component of success in mar-keting
organic grains. Begin researching the market
before the crop is planted. Talk to organic grain buy-ers,
organic certifiers, suppliers, and other organic
grain farmers to gather information on how best to
market your crop. The Internet can be a good re-source
for current information. As a first step, see
“ Marketing Resources” on this Web site:
www. cropsci. ncsu. edu/ organicgrains/ marketing.
marketing. htm.
It is important to know your customers and
know what they want, whether they are brokers,
processors, retailers or end- users. Find out if buyers
are looking for a certain variety of grain or a certain
quantity and whether they have quality specifica-tions
for the grain. Most buyers want to buy organic
grain on a clean, delivered basis. If other arrange-ments
are desired, the farmer may need to negotiate
with the buyer. It is also important to know what
price buyers are willing to pay for grain, and when
and how they will pay. Transportation is another
critical consideration in a marketing plan. How will
the product get to the consumer and when? What are
the costs? Good record- keeping is also a key part of
a marketing plan and will keep a farmer knowledge-able
about how profitable the operation is and where
improvements can be made.
Storage
Storage may be critical for marketing organic grains.
Buyers sometimes do not have sufficient storage
Chapter 9. Marketing Organic Grain and Oilseed Crops
Molly Hamilton, Crop Science Extension Assistant, NC State University
Marketing organic grains is very different from mar-keting
conventional grains. Organic grain is usually
sold to a specific buyer, while a farmer using con-ventional
methods can deposit an entire harvest at
the local grain elevator. For North Carolina farmers,
the organic grain buyers are almost always farther
away from farms than conventional markets, which
means freight costs are an additional consideration.
The National Organic Final Rule ( NOFR) requires
that organic grain be handled, processed, and stored
in facilities separate from conventionally grown and
handled grain. This means that in a split operation
( with both conventional and organic grain produc-tion),
harvesting, transportation, and storage equip-ment
for organic grain needs to be separate in time
or space from equipment used in handling conven-tional
grain. However, organically produced crops
can bring higher prices than conventional crops, so
the extra trouble in getting the crop to market may be
financially beneficial.
The Marketplace
Nearly all organic grains are marketed as either live-stock
feed or as food for human consumption. Or-ganic
grain for human consumption, referred to here
as “ food- grade grain,” generally earns a higher pre-mium
than organic grain for livestock feed. How-ever,
growing for the livestock feed market lowers
the risk of going organic for those who are new to
organic farming. Growing organic grain for the food-grade
market requires a lot of attention to detail and
experience with organic grain production and mar-keting.
Quality specifications are more stringent than
for livestock- feed grain, and markets are usually
harder to identify. Often a specific variety is required
by a buyer of a food- grade grain. For most North
Carolina farmers, the livestock feed market is more
easily accessible than the food- grade grain market.
North Carolina Organic Grain Production Guide 37
capacity, cash- flow, or both to accept an entire
crop at one time. A crop may need to be stored for
several weeks or months. Often, a better price for
the grain is offered a few months after harvest, so
storage may also be an economic advantage. To
maintain grain quality during storage, insects
must be kept out, and the grain must be stored at
proper temperature and moisture conditions. Split
operations will need separate storage bins, or stor-age
bins will need to be thoroughly cleaned
( swept, vacuumed, blown out with pressurized air,
or all of these) to prevent commingling of organic
and conventional products. Storage bins should be
labeled, and records of their contents should be
maintained.
The best way to manage insect pests in stored
organic grains is to avoid them. It is important to
prevent problems in stored grain by keeping bins,
ducts, and augers clean and by storing grain at a
temperature lower than 60° F and at low humidity.
Another suggested and often used method to pre-vent
insect pest problems in stored organic wheat
and corn is to add food- grade diatomaceous earth
( DE) to the grain as it is being loaded into the
storage bins ( at a rate of up to 40 pounds per
1,000 pounds of grain). Diatomaceous earth can
be sprinkled on top of the corn while it is moving
in the auger to the bin, and then on top of the corn
after it is loaded. DE works because the surface of
each particle is very sharp on a microscopic level,
and these sharp edges cut into worms as they feed
or move over the grain, causing them to desiccate.
Be sure to talk to your grain buyer and certifier
before using DE as a storage additive. To identify
insect pests of stored grain, see the North Caro-lina
Small Grain Production Guide or the North
Carolina Corn Production Guide storage sections.
These publications are available through county
Extension centers or on the Web:
http:// www. smallgrains. ncsu. edu/ Guide/ cover. html
http:// www. ces. ncsu. edu/ plymouth/ cropsci/ cornguide/
Genetic Contamination
Organic integrity must be maintained throughout the
growing, harvesting, storage, and transportation
processes. Because organic standards prohibit the
use of genetically modified organisms, proper har-vesting
and storage procedures are an essential part
of organic grain marketing. A positive test result ( a
GMO percentage above a certain level) can cause a
buyer to reject an entire load. If the farm is a split
operation, thorough cleaning of harvest equipment
( including hauling equipment and all augers) be-tween
operations for conventional and organic crops
is very important. Grain- receiving pits, augers or
conveyors, elevator legs, dryers, and storage bins are
all sources of contamination and should be cleaned
to minimize mixing. Running some organic grain at
maximum capacity through the system to clean out
any residual transgenic grain can also help reduce
contamination risks. It may be prudent to harvest the
outside rows of organic grain fields ( especially of
wind- pollinated grains) first and store and sell this
grain as conventional. Doing this eliminates much of
the contamination risk associated with cross- pollina-tion
from transgenic crops.
Transportation
Organic grain buyers generally need the grain deliv-ered
to their facilities and they pay on a delivered
basis. This means that the grower is often respon-sible
for transportation. Trucks that transport grain
from the farm to buyers should be cleaned thor-oughly
before loading organic grain. It is important
to remember to clean the hopper bottoms and any
covering ( such as canvas) on the truck as well as the
bed. Document the cleaning, as this may be needed
by the buyer and the certifier. Documentation can be
a written statement or affidavit that says when and
how the cleaning was done. It shows that the pro-ducer
is taking responsibility for the cleanliness of
the transportation vehicle.
38 North Carolina Organic Grain Production Guide
Grain Quality
Grain quality is very important to food- grade grain
as well as livestock- feed grain. The quality of the
grain determines its value. High- quality grain must
be clean and free of weed seed, undamaged, uncon-taminated,
and identifiable. Controlling weeds, pests,
and volunteer crops in